Home

# DBm to volts formula

dBm, Volts, Watts Conversion dBm is defined as power ratio in decibel (dB) referenced to one milliwatt (mW). It is an abbreviation for dB with respect to 1 mW and the m in dBm stands for milliwatt dBm to Volts Conversion Calculator. Enter an Impedance (Z) and one other value, either Power or Voltage. Select which value you wish to provide as an input using the radio buttons, and it will compute the rest automatically with the result in bold

TYPICAL CONVERSION FORMULAS Collection of frequently used formulas for RF, Microwaves, Power, Voltage, Current and more FIELD STRENGTH & POWER DENSITY POWER dBµV/m to V/m V/m = 10 (((dBµV/m) -120) / 20) dBm to Watts W = 10 ((dBm - 30)/10) V/m to dBµV/m dBµV/m = 20 log(V/m) + 120 Watts to dBm dBm = 10log(W) + 3 3 dBm is actually 1.995 mW but that's near enough for most practical purposes: 10 : 10: Exact +3 : ×2: Adding 3 to the power in dBm is the same as multiplying the power in Watts by two (actually 1.995 but that's near enough for most practical purposes) +10: ×10: Adding 10 the the power in dBm is exactly the same as multiplying the power in Watts by 1  dB µV to Volts V =10 ((dB mV −120)/20) Volts to dB µV dB mV = 20 log (V)+120 dBV to Volts V =10 (dBV /20) Volts to dBV dBV = 20 log (V) dBV to dB µV dB mV = dBV +120 dB µV to dBV dBV = dB mV −120 Log ↔Linear Power dBm to Watts W =10 ((dBm −30)/10) Watts to dBm dBm =10 log( W ) + 30 dBW to Watts W =10 (dBW /10) Watts to dBW dBw =10 log( W ) dBW to dBm dBm = dBW + 3 Power → dBm → Voltage in 50 Ω; Power: dBm: Voltage (RMS) in 50 Ω: 1 kW + 60: 224 V: 100 kW + 50: 70.7 V: 10 W + 40: 22.4 V: 1 W + 30: 7.07 V: 100 mW + 20: 2.23 V: 10 mW + 10: 707 V: 1 mW: 0: 224 V: 100 μW-10: 70.7 W: 10 μW-20: 22.4 mV: 1 μ-30: 7.07 mV: 100 nW-40: 2.23 mV: 10 nW-50: 707 μV: 1 nW-60: 224 μV: 100 pW-70: 70.7 μV: 10 pW-80: 22.4 μV: 1 pW-90: 7.07 μV: 100 fW-100: 2.23 μV: 10 fW-110: 0.71 μV: 1 fW-120: 0.2

This table shows the relationship between Power in [dBm] or [Watts] and Voltage in RMS, peak, peak-to-peak for sinusoidal signals in 50-Ohm systems . [dBm] [Watts] [Volts]rms. [Volts]p. [Volts]pp. -180. .100E-20. 0.224 nV 24.0 dBm The formulas used to convert between units are: ire =Volts_peak_to_peak*140 Volts_rms =Volts_peak_to_peak/SQRT(8) Volts_peak_to_peak =Volts_rms*SQRT(8) dBm =20*LOG10(Volts_peak_to_peak/SQRT(0.008*Z)) dBmv =20*LOG10(Volts_rms/0.001

Aber im Grunde ist ja alles gesagt: dBm ist eine Leistungsangabe und es entspricht 0 dBm einer Leistung von 1 mW. Das Volt hingegen ist eine Spannungsangabe, was du eigentlich schon aus der Schule kennen solltest. Außerdem solltest du 2 Formeln kennen: P=U*I und U=R*I, womit du dir alles Benötigte selbst darstellen und ausrechnen kannst. W.S dBm to Volts Conversion Calculator. Try our new dBm to voltage calculator! Enter a Z value and one other value. dBm: Vpp: Vrms: Z (Ohms): dBm P(dBm) 10: 7.07107: 6.36620: 1.00000: 1000.00000: 30.00000: 9: 6.36396: 5.72958: 0.81000: 810.00000: 29.08485: 8: 5.65685: 5.09296: 0.64000: 640.00000: 28.06180: 7: 4.94975: 4.45634: 0.49000: 490.00000: 26.90196: 6: 4.24264: 3.81972: 0.36000: 360.00000: 25.56303: 5: 3.53553: 3.18310: 0.25000: 250.00000: 23.97940: 4: 2.82843: 2.54648: 0.16000: 160.00000: 22.04120: 3.162278: 2.23607: 2.01317: 0.10000: 100.00000: 20.00000: 3: 2.12132: 1.90986: 0.0900 TYPICAL CONVERSION FORMULAS LOG -> LINEAR VOLTAGE FIELD STRENGTH & POWER DENSITY dBµV to Volts V = 10 ((dBµV - 120) / 20) dBµV/m to V/m V/m = 10 (((dBµV/m) -120) / 20) Volts to dBµV dBµV = 20 log(V) + 120 V/m to dBµV/m dBµV/m = 20 log(V/m) + 12

dB Log dB Volts 2 20 1 Volts Volts dB Log dB Amps 2 20 1 Amps Amps dB Log New Watts w/dB 10 10 ( ) 10 dB Log Wattsstart WattsNew New Volts w/dB 20 20 ( ) 10 dB Log Voltsstart VoltsNew New Amps w/dB 20 20 ( ) 10 dB Log Ampsstart AmpsNew dB Correction for distance change (antenna far field) 1 2 distance distance dB 20 Log A Amps V Volts Ohms Ω Watts W W V W The damping factor, also called loss, is the extent to which a passive device reduces the strength of a signal. Amplification means voltage ratioV2/ V1= Vout/ Vin, and voltage gain in dB = 20 × log (V2/ V1). V1= 1 Volt. The used browser does not support JavaScript mW (milliwatt) uW (microwatt) nw (nanowatt) dB value: value: - Use the dBm to watt calculatorto convert from dBm to watt and vice versa. - Use the dBuV to volt calculatorto convert from dBuV to volt and vice versa To convert this to decibel, use the formula: Gain (dB) = 20 * log (Vout/Vin) = 20 * log (Voltage Gain) If Vin = 1Volt, and Vout = 2Volts, then Voltage Gain = 2 dB Volts Formula. The formula used to perform this calculation is below. Remember to convert all units to volts when using the dB Volts Formula. dB Volts Formula: where: • dB = Decibels • V out = Output Voltage • V in = Input Voltag

4,0 dBm 354 mV 2,5119 mW 3,0 dBm 316 mV 1,9953 mW 2,0 dBm 282 mV 1,5849 mW 1,0 dBm 251 mV 1,2589 mW 0,0 dBm 224 mV 1,0000 mW-1,0 dBm 199 mV 0,7943 mW-2,0 dBm 178 mV 0,6310 mW-3,0 dBm 158 mV 0,5012 mW-4,0 dBm 141 mV 0,3981 mW-5,0 dBm 126 mV 0,3162 mW-6,0 dBm 112 mV 0,2512 mW-7,0 dBm 100 mV 0,1995 m Convert RF microvolts or millivolts to dBuV, dBmV, or dBV. Convert dBuV, dBmV, or dBV to microvolts or millivolts. Free online calculators In expressing sensitivity of radio receivers, signal levels are often expressed in dB relative to 1 micro Volt (µV). There is a common practice to write this as dBuV rather than dBµV due to shortcomings of the character set in some contexts. dBµV may be qualified as 'emf' meaning it is the unloaded voltage of the source, otherwise it should be taken as the terminal voltage of a source. Answer (1 of 2): dBv is a logarithmic voltage ratio with a voltage reference of 1 Volt. 1 V is equivalent to 0 dBv. The formula for Volts to dBv conversion is: And hence, the reverse formula for dBv to Volts conversion is Convert from dBuV. Enter a value for the units below and press calculate. Convert from. dBμV with Z = Ω. d B μ V − 60 =. dBmV. d B μ V − 120 =. dBV. d B μ V − 20 ⋅ l o g 10 ( Z) =

### dBm, Volts, Watts Conversion - A

1. dBm - Watts - Volts conversion table. This conversion table charts the values for dBm against milliwatts and the relevant voltage expressed in volts. It is applicable to many high power applications. These tables of dBm, dBW, watts and miliwatts to volts are useful to discover the voltages present. Converting from dBm and from the other values.
2. The power conversion of dBm to watts is given by the formula: P (W) = 1W ⋅ 10 (P (dBm) / 10) / 1000 = 10 ((P (dBm) - 30) / 10) Example. Convert 43dBm to watts: P (W) = 1W ⋅ 10 (43dBm/ 10) / 1000 = 19.9526W. dBm to watts conversion table. Power (dBm) Power (W)-30 dBm: 0.000001 W-20 dBm: 0.00001 W-10 dBm: 0.0001 W: 0 dBm: 0.001 W: 1 dBm: 0.0012589 W: 2 dBm: 0.0015849 W : 3 dBm: 0.0019953 W.
3. Re: Volts to dBm Formula. That, or for a voltage into a 50 ohms line or load, just do P [dBm] = 20 * log10 (Volts) + 13. Power e.g. Pout = V*V/R, where V is in Volts RMS and R in Ohms, R is typically 50. For dBm Pin is 1 mW or 0.001 Watts
4. From: parc-homebrew@parc.groups.io [mailto:parc-homebrew@parc.groups.io] On Behalf Of Peter Ayearst Sent: 15-Dec-17 12:08 PM To: parc-homebrew@parc.groups.io Subject: [parc-homebrew] Volts to dBm Formula Anyone know off hand the formula to calculate either Vpp or Vrms to dBm? I can find calculators ok but I want the formula. I can find some formulas but not exactly what I want.-- 73, Peter.
5. DeciBel dB: Formulas Equations & Calculations The deciBel, dB is a logarithmic scale used for comparing two physical quantities especially in electronics. There are several easy to remember formulas that enable the values to be calculated . Decibels, dB Tutorial Includes: Decibels, dB - the basics Decibels levels table dBm to dBW & power conversion chart dBm to watts and volts conversion chart.
6. dBm - volts - watts conversion 030609 53 99.9 200 0 0.224 1.00 -49 0.79 -98 2.8 50 70.7 100 -1 0.199 0.79 -50 0.71 .01 µW -99 2.51 49 63.0 79 -2 0.178 0.63 -51 0.63 -100 2.24 .1 pW 48 56.2 63 -3 0.158 0.50 -52 0.56 -101 2.  ### dBm to Voltage Converter - coretechgroup

The dBm is referenced to 1mW. Equation 3 does depend on impedance of the load as shown in Equation 4. Most RF equipment has a 50Ω load or input impedance. Equation 3 is still valid for any load impedance including 75Ω. Power depends on load impedance. Equation 4 equates power to voltage and load impedance. Rearranging terms, Solving Equation 3 for P OUT, Solving Equation 1 for V OUT. Power vs. Voltage. This table shows the relationship between Power in [dBm] or [Watts] and Voltage in RMS, peak, peak-to-peak for sinusoidal signals in 50-Ohm systems . [dBm] [Watts] [Volts]rms. [Volts]p. [Volts]pp

CONVERSION CHART dBm <=> Watts <=> Vrms <=> V pp Note: The power to voltage conversions shown are valid only for Sine Waves and 50 Ohm Load Impedance. This chart is a handy reference when tinkering with oscilloscope and spectrum analyzer displays. dBm W Vrms Vpp dBm W Vrms Vpp 40 10.0 W 22.4 _V 63.2 _V-6 251.2_uW 112.1 _mV 317.0 _mV 39 7.9 W 19.9 _V 56.4 _V-7 199.5_uW 99.9 _mV 282.5 _mV 38 6.3. Conversion of dBm to mW, Veff, Vp and Vpp: P dBm 10 log10 P 1mW ð / 10 10 P dBm P mW P Veff /R 2 ð VPR eff For sinusoidal signals: Vpeak 2 Veff and Vpp 2 Vpeak For sinusoidal signals and for R = 50 Ω the following table can be used: P [dBm] P [mW] Veff [V] Vp [V] Vpp [V] P [dBm] P [mW] Veff [V] Vp [V] Vpp [V] -30 0.001 0.007 0.010 0.020 0 1.000 0.224 0.316 0.632 -29 0.001 0.008 0.011 0.022.

### Video:  dBm is defined as power ratio in decibel (dB) referenced to one milliwatt (mW) and the m in dBm stands for milliwatt. With the known impedance value you can convert voltage V to level dBm (power) and vice versa. Reference voltage at 600 ohms- 1 mW according to 0 dBm Reference voltage at 50 Ohm - 1 mW according to 0 dBm: Enter two values, the third value will be calculated. Voltage V, level L. Voltage to dBm conversion. The power level of radio-frequency energy is often expressed in decibels above one milliwatt. This spreadsheet calculates the following: The power in watt and dBm with a given voltage and impedance. The power in dBm with a given power and impedance. The voltage in millivolts with a given power and impedance

### Watts <> dBm <> Volts Converte

(dBm) volts/meter 162.8 42.8 -17.2 µ v/meter 42.8 -77.2 -137.7 FIELD STRENGTH APPROACH To account for the impedance difference, th e antenna factor (AF) is defined as: AF=E/V, where E is field intensity which can be expressed in terms taking 377 o hms into account and V is measured voltage which can be expressed in terms taking 50 ohms into account. Details are provided in Section 4-12. POWER. Volt per meter and Power density calculator: Power: W: Transmit power in watt: Gain: dBi: Antenna gain in dBi: Distance: m: Distance in meters: Value: V/m dBuV/m dBm/m2 - Calculates the field strength in a free field. The calculation is only valid in the far field (depends on antenna size and wave length). - Usually this calculation will be an approximation of the real field strength due to. dBm to Watt. RF Engineers often express the power in dBm in place of Watts. The formula converts a power expressed in dBm to Watt and Vice Versa. Following is the formula for dBm to Watt conversion. P (dBm) = 10 log 10 (p/p 0) Where p 0 is the reference volatge and is 1mW or 1x10 -3 Watts. To Calculate dBm from wattage enter the value in P. RF Calculator: Wavelength, dBm, dBuV, W, dBuV/m, mW/cm^2, pJ/cm^2, V & VSWR This RF calculator has been developed by Compliance Engineering as a resource for individuals involved in EMC and RF compliance measurements. The following table provides conversions for wavelength (from frequency), VSWR (from forward and reflected power) and various other useful conversions. Try our [

### Umrechnung Power - dbm - V BOS Antennen - Amphenol

dBm to volts Calculator - Reference Designer › See more all of the best online courses on www.referencedesigner.com Courses. Posted: (6 days ago) Following is the formula for dBm to RMS voltage conversion. P (dBm) = 10 log 10 (v 2 / (R*p 0 )) Where p 0 is the reference wattage and is 1mW or 1x10 -3 watts dBm is a power ratio relative to 1mW, dBu and dBV are voltage ratios, relative to 0.775V and 1V, respectively. To use this calculator enter your application data in the section provided, then enter the quantity you wish to convert in the appropriate form element. Tabbing to another field, pressing Enter or clicking Calculate will recompute all equivalent values. Please be aware of the. See the relationship between power in dBm, Watts and RMS Voltage. This is relevant for many power applications Whether expressed in watts or volts, the small numbers clearly are quite cumbersome to handle. Surely there must be a better way. There is: the decibel. Mathematically, dBmV = 20log 10 (mV/1 mV), where mV in the numerator is the voltage in millivolts that is to be converted to dBmV. Yes, what you see in this formula suggests voltage is the reference and, in fact, it is. But we get. ### Table: Power vs. dBm and Volts - uni-hamburg.d

Following equation or formula is used for dBm to dBW converter and viceversa. Useful converters and calculators. Following is the list of useful converters and calculators. dBm to Watt converter Stripline Impedance calculator Microstrip line impedance Antenna G/T Noise temp. to NF. dBm related links . dB,dBm,dBW,dBC dBm,dBmV,dBuV. RF and Wireless tutorials. WLAN 802.11ac 802.11ad wimax Zigbee. Volts rms to dBm Zo : Ohms V1 : Volts power = 20 Log (V1/(0.001 x Zo)^0.5) Power = dBm Update Reset Print. To use the calculator below, input a value into the field and hit the enter key. The result will appear below. You can choose different calculations from the drop down menu. Note that to convert from dBm to dBW, simply subtract 30 from the dBm value. For example: 30 dBm = 0 dBW, which is another way of saying that 1,000 milliwatts equals one Watt

### Coversion table: Volts-to-dB

859xE: How Do You Convert from dBm/Hz to Volts/Root (Hz)? Use the formula P=V*V/R and solve for V How to convert dBm to Watts formula and conversion table. Search. Home; About us; Products. PIM. 320 - 480 MHz PIM Analyzers. Lab, QA and field: Single Band; Production & R&D: Single Band ; 690 - 3500 MHz PIM Analyzers. Lab & QA: Single Band; Production: Single Band; Production & R&D: Multi Band; Production & R&D; Multi Band (automatic) & S-Parameters; Portable: Single / Double Band; Low. If we look at the sequence above, that's 4 stops difference. Let's check using the formula above: (√2)⁴ ∙ 1.4 = 4 ∙ 1.4 = 5.6. As you can see the f-stop values make a logarithmic scale! More information about exposure value and f-number. There are many other relative logarithmic values and units like the absorbance in chemistry and physics, the apparent magnitude of a celestial.

### Wie stehen dBm und Volt zueinander? - Mikrocontroller

Bal Chand Nagar. National Institute of Technology Patna. The defining equation for decibels is. A = 10*log10 (P2/P1) (dB) where P1 is the power being measured, and P1 is the reference to which P2. Answer (1 of 9): dBs are ten times the base 10 logarithm of two power ratios. Power is related to voltage by the relationship P=(V^2)/R, so you have to know what R is if you want to convert a voltage measurement into a power one. You can only convert from one to the other meaningfully if you me.. 50 ohm dBm to microVolt Conversion Table Copyright ©©©© 2007 Robert W. Meister / WA1MIK 2 dBm uV -60.0 223.607 -59.5 236.856 -59.0 250.89 Power (dBm) Power (watt)-3 dBm 0.0005 W -2 dBm 0.0006 W -1 dBm 0.0008 W 0 dBm 0.001 W 1 dBm 00013 W 2 dBm. ### dbm calc - Core Technology Grou

• dBm (sometimes dB mW or decibel-milliwatts) is an abbreviation for the power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW).. dBm (sometimes dB mW or decibel-milliwatts) is an abbreviation for the power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW).. Conversion from dBm with Z=50Ω impedance to µ
• Formula for converting dBm to watts. P (W) = 1 W x 10 (P (dBm) / 10) / 1000 = 10 ((P (dBm) - 30) / 10) This means that the power conversion of decibel-milliwatts to watts is given by 10 raised to the power of decibel-milliwatts divided by 10 and the result is then divided by one thousand. Using the example above; Convert 0.15 decibel-milliwatts to watts, The calculation will be; 1 W x 10 (0.15.
• In signal generator, to see the dBm value, I press Channel Power icon to see the dBm value and it shows -60dBm when transmits. So to find the gain, do I need to calculate as below: 10 log Pout( in dBm) / Pin(in dBm) = ? dBi Pout = -60dBm (at signal generator) Pin= -10dBm ( at sweep oscillator) So , if I follow the formulae above, I'm getting.
• Formula used: dB = 10 • log 10 ( Power 1 / Power 2 ) 1 Bel = 10 decibels (dB) dB Voltage Ratio Calculator. Enter TWO Voltage values, (use same units for both: Kilovolts, Volts, Millivolts etc.) then click CALC. Voltage 1 (output) Voltage 2 (input) Decibels (dB) = Formula used: dB = 20 • log 10 ( Voltage 1 / Voltage 2 ) 1 Bel = 10 decibels (dB) Decibel The decibel (dB) is a unitless.
• V m = 10 (dB μ V m / 20) 1, 000, 000 V m = 10 (dB μ V m / 20) 1, 000, 000 (dB μ V)/m (dB μ V)/m . Tags. Conversions Electrical Electrical Engineering Unit Conversions Electromagnetic Verified. UUID. e6d41750-da27-11e2-8e97-bc764e04d25f. The dBμV/m-to-V/m calculator converts decibel microvolts per meter to volts per meter. INSTRUCTIONS: Enter the following: (dBμV/m) This is the decibel.

### Voltage to power conversion in 50 Ohm System Equations

• If you need to calculate dB from the comparison of two voltages or amplitudes, use the dB Volts Formula Calculator instead. The calculator below finds the decibel-milliwatts (dBm) for a given power in watts. dBm Watts Calculator. Watts Out Decibel-milliwatts: dBm dBm Watts Formula. The formula used to perform the Wattage to dBm calculation is below. Remember to convert all units to watts when.
• With dB and ratio near the input boxes, we decide what is calculated and which box is the input. With size of a field and size of energy we decide if it is 20 times (field quantity, e.g. volts) or 10 times (energy quantity, or power quantity, e.g. watts) in the formula
• RF Power Conversion Calculator. Pasternack's RF Power Conversion Calculator allows you to convert RF input power and RF output power values from variables such as milliwatts (mW), Watts, dBm, dBW, millivolts (mV), and Volts. **Note: All of our calculators allow SI prefix input. For example, if you wish to input 25000000, just type 25M instead
• dB is not a measurement unit like ,for instance, volts are. It is a ratio between two quantities of the same type. The last equation is correct and can be used to represent a gain or a loss, in dB. In fact if you have a voltage gain of, lat me say, 1000 means the ouptut voltage Vo will be 1000*Vi (input voltage). Using the last equation we will.
• dBm (dB over 1 milliwatt) is power and µV is voltage, they are different units so we need to know their relationship before converting them. We need to know the source or load resistance so we can use this basic equation: \(P=V^2/R\) Where P is the power in watts, V is the RMS (root mean square) voltage in volts, and R is the resistance in ohms

### Decibels to Voltage Gain and Loss convert calculation

• Decibels (dB) are used to express power ratios in a logarithmic way, so that very large and very small powers can be compared using comfortable numbers. A decibel is a dimensionless pseudo-unit because it's defined by the ratio of two powers. But since decibels are so handy, to express true power instead of just a dimensionless ratio, referenced decibels are very often used. If we talk about.
• The actual formula used for the conversion is: dBm = log (mW) * 10. Converting Signal Strength Percentage to dBm Values The Receive Signal Strength Indicator (RSSI) Page 4 What you can see in the graph is that there is a relatively linear appearance to the slope as it rises from -100 dBm to the point where the mW value is roughly 5. At that point, the.
• dB is denoted for Decibel. dB is a ratio of input signal level to the output signal level. It is used for RF devices like Splitters and amplifiers . Input Signal level defined as mV µV nV but these units are having large magnitude. We need to use short units. These short units are defined as dBm dBmV dBuV. Thus there are two kind of voltages. First is Source Voltage and second is Potential.
• EXAMPLE#1: INPUT: Power in dBm = 40 OUTPUTS: Vrms = 22.360 Volts Vpeak = 31.618 Volts Vp-p = 63.236 Volts Power to Vrms, Vpeak, Vp-p conversion formula or equation. Following equations or formula are used for Power to Vrms/Vpeak/Vp-p conversion
• Power (dBm) 0 W not defined 0 + W -∞ dBm 0.00001 W -20 dBm 0.0001 W -10 dBm 0.001 W 0 dBm 0.01 W.
• DB to Watts Formula. The following formula is used to convert dBm to watts. W = 10^((dBm-30)/10)) Where W is the power in watts; dBm is the decibel-milliwatts; Db to Watts Definition. Converting dB to watts is actually the process of converting decibel-milliwatts to watts since decibel in itself is just a unitless factor. Db to Watts Exampl

dBm TO MICROVOLTS CONVERSION CHART (For 50 Ω System) dBm uV dBm uV dBm uV 0 224,000 -47 1,000 -94 4.4 Convert 20 dBm to milliwatts: P (mW) = 10 (20/10) = 100 mW. So, the power of 20 dBm is equal to 100 mW or 0.1 W (Watt). Example 2: Convert -30 dBm to milliwatts: P (mW) = 10 (-30/10) = 0.001 mW. So, the power of -30 dBm is equal to 0.001 mW or 0.000001 W = 1 μW The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B).It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale.Two signals whose levels differ by one decibel have a power ratio of 10 1/10 (approximately 1.26) or root-power ratio of 10 1 ⁄ 20 (approximately 1.12).. The unit expresses a change in value (e.g., +1 dB or. To calculate volts from watts, we need to rearrange this formula by expressing voltage like this: Volt = Watts / Amps. To convert watts to volts, we need to know how many amps does the electrical circuit has. Example 1: 1 volt is equal to how many watts? If you have a 1 amp circuit, 1 volt is equal to 1 watt. If you have a 100 amp circuit, 1. dBm is referenced to one milliwatt (0.001 W). dBW value in dBm is always 30 more because 1 watt is 1000 milliwatts, and ratio of 1000 (in power) is 30 dB, eg 10 dBm (10mW) is equal to -20 dBW (0.01 W). Input a value above, select the type of unit you wish to convert, and click the 'Convert My Power' button. All calculated values will be shown is the formula that DBm=DB+30 and DB=DBm-30. 15th April 2012 at 07:30 #68077 Reply. pix. Guest. misa, no, that is very very wrong. dB cannot be converted in dBm ! those are not counting the same thing. dBm is an absolute power. It can be converted in Watts. 2W = 33dBm. dB is a difference of dBm, and it has no physical existence other than this. It is a mathematical tool. For example, from.