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# The dbm Calculator & Reference table for 50 Ohms

What is dBm?
A logarithmic ratio with a reference power of P0 = 1.000 milliwatt = 0 dBm.
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, and impedance
Z

 Voltage V V RMS Power level L dBm re 1 mW Impedance Z Ω

Table based on 50 Ohms

 Vrms dBm Watts Vrms dBm Watts Vrms dBm Watts μV dBm mV dBm V dBm W 0.7 -110 10 fW 1.1 -46 1.1 +14 0.025 0.8 -109 S 3 1.2 -45 1.2 +15 0.032 0.9 -108 1.4 -44 1.4 +16 0.04 1 -107 1.5 -43 S 9 +30 1.5 +17 0.05 1.1 -106 1.7 -42 1.7 +18 0.063 1.2 -105 1.9 -41 1.9 +19 0.08 1.4 -104 2.2 -40 100 nW 2.2 +20 0.1 W 1.5 -103 S 4 2.5 -39 2.5 +21 0.13 1.7 -102 2.8 -38 2.8 +22 0.16 1.9 -101 3.1 -37 3.1 +23 0.2 2.2 -100 100 fW 3.5 -36 3.5 +24 0.25 2.5 -99 3.9 -35 3.9 +25 0.3 2.8 -98 4.4 -34 4.4 +26 0.4 3.1 -97 S 5 5 -33 S 9 +40 5 +27 0.5 3.5 -96 5.6 -32 5.6 +28 0.63 3.9 -95 6.3 -31 6.3 +29 0.8 4.4 -94 7 -30 1 µW 7 +30 1 W 5 -93 S9 VHF/UHF 7.9 -29 7.9 +31 1.2 5.6 -92 8.9 -28 8.9 +32 1.5 6.3 -91 S 6 9.9 -27 9.9 +33 2 7 -90 1 pW 11 -26 11.2 +34 2.5 7.9 -89 13 -25 12.5 +35 3.1 8.9 -88 14 -24 14.1 +36 3.9 9.9 -87 15 -23 15.8 +37 5 11 -86 17 -22 17.7 +38 6.3 13 -85 S 7 19 -21 19.9 +39 7.9 14 -84 22 -20 10 µW 22.3 +40 10 W 16 -83 25 -19 18 -82 28 -18 20 -81 32 -17 22 -80 10 pW 35 -16 25 -79 S 8 40 -15 28 -78 45 -14 32 -77 50 -13 35 -76 56 -12 40 -75 63 -11 45 -74 71 -10 100 µW 50 -73 S 9 79 -9 56 -72 89 -8 63 -71 100 -7 71 -70 100 pW 112 -6 79 -69 126 -5 89 -68 141 -4 100 -67 158 -3 112 -66 178 -2 126 -65 199 -1 141 -64 224 0 1 mW 158 -63 S 9 +10 251 +1 177 -62 282 +2 200 -61 316 +3 223 -60 1 nW 354 +4 251 -59 398 +5 282 -58 446 +6 316 -57 501 +7 354 -56 562 +8 398 -55 630 +9 446 -54 707 +10 10 mW 500 -53 S 9 +20 793 +11 561 -52 890 +12 630 -51 1000 +13 707 -50 10 nW 793 -49 890 -48 1000 -47