DBm Conversion Table

A Useful Conversion chart for making sure that you do not Blow-up any Test Equipment.

You should always use a DC Block on a Spectrum Analyser and if checking out say a 100W Radio and you want to test the radio to the 100 W Max, then you need to also use a 50 DBm Attenuator.

Always check the Input terminals on a Spectrum Analyser to see what the Max Voltage is that they recommend, Exceeding this or even not using the correct attenuator will blow up your precious Spectrum Analyser.

You should be able to work out other values from the chart below.

DBm	Watts	Voltage (P-P)	Voltage RMS
-30	0.0010 mW	20.0 mW	7.0 mV
-28	0.0016 mW	25.1 mW	8.9mV
-26	0.0025 mW	31.6 mW	11.2 mV
-24	0.0040 mW	39.9 mW	14.1 mV
-22	0.0063 mW	50.2 mW	17.7 mV
-20	0.010 mW	63.2 mW	22.3 mV
-18	0.016 mW	79.6 mW	28.1 mV
-16	0.025 mW	100 mW	35.4 mV
-14	0.040 mW	126 mW	44.6 mV
-12	0.063 mW	158 mW	56.1 mV
-10	0.100 mW	200 mW	70.7 mV
-8	0.16 mW	251 mW	89.0 mV
-6	0.25 mW	316 mW	112 mV
-4	0.40 mW	399 mW	141 mV
-2	0.63 mW	502 mW	177 mV
0	1.00 mW	632 mW	223 mV
2	1.58 mW	796 mW	281 mV
4	2.51 mW	1.00 V	0.33 V
6	3.98 mW	1.26 V	0.44 V
8	6.31 mW	1.58 V	0.56 V
10	10 mW	2.00 V	0.70 V
12	15.8 mW	2.51 V	0.89 V
14	25.1 mW	3.16 V	1.12 V
16	39.8 mW	3.99 V	1.41 V
18	63.1 mW	5.02 V	1.77 V
20	100 mW	6.32 V	2.23 V
22	158 mW	7.96 V	2.81 V
24	251 mW	10.0 V	3.54 V
26	398 mW	12.6 V	4.46 V
26.99	500 mW	14.1 V	5.00 V
28	631 mW	15.8 V	5.61 V
30	1.00 W	20.0 V	7.10 V
32	1.58 W	25.1 V	8.90 V
33.01	2.00 W	28.2 V	9.99 V
34	2.51 W	31.6 V	11.2 V
34.77	3.00 W	34.6 V	12.2 V
36	3.98 W	39.9 V	14.1 V
36.02	4.00 W	39.9 V	14.1 V
36.99	5.00 W	44.7 V	15.8 V
38	6.31 W	50.2 V	17.7 V
40	10.0 W	63.2 V	22.3 V
42	15.9 W	79.6 V	28.1 V
43.01	20 W	89.4 V	31.6 V
44	25.1 W	100.2 V	35.4 V
44.77	30 W	109.5 V	38.7 V
46	39.8 W	126.1 V	44.6 V
46.02	40 W	126.4 V	44.7 V
46.99	50 W	141.4 V	50.0 V
47.78	60 W	149.6 V	52.9 V
48	63.1 W	158.8 V	56.1 V
48.45	70 W	167.3 V	59.1 V
49.03	80 W	178.8 V	63.2 V
49.54	90 W	189.6 V	67.0 V
50	100 W	200.0 V	70.7 V
52	159 W	251.7 V	89.0 V
53.1	200 W	285.7 V	101.0 V
54	251 W	316.9 V	112.0 V
56	398 W	399.0 V	141.0 V
56.2	400 W	408.3 V	141.3 V
58	631 W	502.3 V	177.6 V
60	1000 W	632.4 V	223.6 V