mW to dBm Calculator

Use this tool to convert from milliWatt to dBm.

You can select either Watt, Milliwatt, Microwatt, Nanowatt or Picowatt.

🔄 dBm to milliWatt

Formula

PdBm = 10*Log10(PmW)

What is dBm?

dBm is a unit of power expressed in deciBels referenced to one milliwatt [1]. It is commonly used in Radio frequency, Microwave and Optical communication systems as a measure of absolute power. dBm makes it easy to represent both very large and very small values with few digits.

For example 10,000,000,000,000 mW = 1013 mW = 130 dBm

As well, it makes RF budget calculations simpler than with linear values.

What is a Milliwatt?

Milliwatt is a unit of power. It is equivalent to 1/1000 of a Watt. Or 1 mW = 0.001 Watt.

Note the small m to denote milli and not to be confused by capital M which denotes Mega or 106.

How to convert from Milliwatt to dBm

The calculation: 10*Log10(1)= 0 dBm.

1 milliWatt is therefore equal to 0 dBm. 

1000 milliwatt is equal to 30 dBm.

These two numbers are often used by RF engineers and a baseline from which other calculations can be performed.

Let’s take a look at an example below.

What is the dBm equivalent of 2 milliWatt? The same calculation can be performed to give 10*Log10(2) = 10*0.301 = 3 dBm.

Alternatively, we can see that 2 milliWatt is equivalent to two times 1 milliWatt or it represents a ratio of 2:1. This is linear ratio is equivalent to 3 dB. Therefore we can add 3 dB + 0 dBm to give 3 dBm.

With practice is becomes easier to identify these relationships for quick mental conversions but until then you can use the calculator on this page.

Why convert from milliwatt to dBm?

Many times a manufacturer will specify their product in terms of Watt. The power amplifier below is one such example.

BTECH AMP-U25 Amplifier for UHF (400-480MHz), 20-40W Output (2-6W Input), Analog and Digital Modes, Compatible with All Handheld Radios: BTECH, BaoFeng, Kenwood, Yaesu, ICOM, Motorola

However RF engineers will convert this to dBm. Here are a couple of reasons why:

dBm makes it easy to express large numbers. Numbers with many zeros as shown below can be expressed with a smaller number of dBm. For example:

  • 0.0000000001 milliWatt = -100 dBm
  • 1.0000E-17 mW = -170 dBm
  • 10000 mW = 100 dBm

The Logarithmic scale makes this possible.

dBm is convenient to work with. Most RF calculations such as Antenna RangeWi-Fi RSSI and more are performed using dBm power levels. dBm is also used in conjunction with dB to compute input and output power levels. This involves simple addition or subtraction operations.

mW to dBm Table

Below is a chart of milliWatt to dBm values ranging from 1 mW to 1000 mW.

mWdBm
10.0000
23.0103
34.7712
46.0206
56.9897
67.7815
78.4510
89.0309
99.5424
1010.0000
1110.4139
1210.7918
1311.1394
1411.4613
1511.7609
1612.0412
1712.3045
1812.5527
1912.7875
2013.0103
2113.2222
2213.4242
2313.6173
2413.8021
2513.9794
2614.1497
2714.3136
2814.4716
2914.6240
3014.7712
3114.9136
3215.0515
3315.1851
3415.3148
3515.4407
3615.5630
3715.6820
3815.7978
3915.9106
4016.0206
4116.1278
4216.2325
4316.3347
4416.4345
4516.5321
4616.6276
4716.7210
4816.8124
4916.9020
5016.9897
5117.0757
5217.1600
5317.2428
5417.3239
5517.4036
5617.4819
5717.5587
5817.6343
5917.7085
6017.7815
6117.8533
6217.9239
6317.9934
6418.0618
6518.1291
6618.1954
6718.2607
6818.3251
6918.3885
7018.4510
7118.5126
7218.5733
7318.6332
7418.6923
7518.7506
7618.8081
7718.8649
7818.9209
7918.9763
8019.0309
8119.0849
8219.1381
8319.1908
8419.2428
8519.2942
8619.3450
8719.3952
8819.4448
8919.4939
9019.5424
9119.5904
9219.6379
9319.6848
9419.7313
9519.7772
9619.8227
9719.8677
9819.9123
9919.9564
10020.0000
10120.0432
10220.0860
10320.1284
10420.1703
10520.2119
10620.2531
10720.2938
10820.3342
10920.3743
11020.4139
11120.4532
11220.4922
11320.5308
11420.5690
11520.6070
11620.6446
11720.6819
11820.7188
11920.7555
12020.7918
12120.8279
12220.8636
12320.8991
12420.9342
12520.9691
12621.0037
12721.0380
12821.0721
12921.1059
13021.1394
13121.1727
13221.2057
13321.2385
13421.2710
13521.3033
13621.3354
13721.3672
13821.3988
13921.4301
14021.4613
14121.4922
14221.5229
14321.5534
14421.5836
14521.6137
14621.6435
14721.6732
14821.7026
14921.7319
15021.7609
15121.7898
15221.8184
15321.8469
15421.8752
15521.9033
15621.9312
15721.9590
15821.9866
15922.0140
16022.0412
16122.0683
16222.0952
16322.1219
16422.1484
16522.1748
16622.2011
16722.2272
16822.2531
16922.2789
17022.3045
17122.3300
17222.3553
17322.3805
17422.4055
17522.4304
17622.4551
17722.4797
17822.5042
17922.5285
18022.5527
18122.5768
18222.6007
18322.6245
18422.6482
18522.6717
18622.6951
18722.7184
18822.7416
18922.7646
19022.7875
19122.8103
19222.8330
19322.8556
19422.8780
19522.9003
19622.9226
19722.9447
19822.9667
19922.9885
20023.0103
20123.0320
20223.0535
20323.0750
20423.0963
20523.1175
20623.1387
20723.1597
20823.1806
20923.2015
21023.2222
21123.2428
21223.2634
21323.2838
21423.3041
21523.3244
21623.3445
21723.3646
21823.3846
21923.4044
22023.4242
22123.4439
22223.4635
22323.4830
22423.5025
22523.5218
22623.5411
22723.5603
22823.5793
22923.5984
23023.6173
23123.6361
23223.6549
23323.6736
23423.6922
23523.7107
23623.7291
23723.7475
23823.7658
23923.7840
24023.8021
24123.8202
24223.8382
24323.8561
24423.8739
24523.8917
24623.9094
24723.9270
24823.9445
24923.9620
25023.9794
25123.9967
25224.0140
25324.0312
25424.0483
25524.0654
25624.0824
25724.0993
25824.1162
25924.1330
26024.1497
26124.1664
26224.1830
26324.1996
26424.2160
26524.2325
26624.2488
26724.2651
26824.2813
26924.2975
27024.3136
27124.3297
27224.3457
27324.3616
27424.3775
27524.3933
27624.4091
27724.4248
27824.4404
27924.4560
28024.4716
28124.4871
28224.5025
28324.5179
28424.5332
28524.5484
28624.5637
28724.5788
28824.5939
28924.6090
29024.6240
29124.6389
29224.6538
29324.6687
29424.6835
29524.6982
29624.7129
29724.7276
29824.7422
29924.7567
30024.7712
30124.7857
30224.8001
30324.8144
30424.8287
30524.8430
30624.8572
30724.8714
30824.8855
30924.8996
31024.9136
31124.9276
31224.9415
31324.9554
31424.9693
31524.9831
31624.9969
31725.0106
31825.0243
31925.0379
32025.0515
32125.0651
32225.0786
32325.0920
32425.1055
32525.1188
32625.1322
32725.1455
32825.1587
32925.1720
33025.1851
33125.1983
33225.2114
33325.2244
33425.2375
33525.2504
33625.2634
33725.2763
33825.2892
33925.3020
34025.3148
34125.3275
34225.3403
34325.3529
34425.3656
34525.3782
34625.3908
34725.4033
34825.4158
34925.4283
35025.4407
35125.4531
35225.4654
35325.4777
35425.4900
35525.5023
35625.5145
35725.5267
35825.5388
35925.5509
36025.5630
36125.5751
36225.5871
36325.5991
36425.6110
36525.6229
36625.6348
36725.6467
36825.6585
36925.6703
37025.6820
37125.6937
37225.7054
37325.7171
37425.7287
37525.7403
37625.7519
37725.7634
37825.7749
37925.7864
38025.7978
38125.8092
38225.8206
38325.8320
38425.8433
38525.8546
38625.8659
38725.8771
38825.8883
38925.8995
39025.9106
39125.9218
39225.9329
39325.9439
39425.9550
39525.9660
39625.9770
39725.9879
39825.9988
39926.0097
40026.0206
40126.0314
40226.0423
40326.0531
40426.0638
40526.0746
40626.0853
40726.0959
40826.1066
40926.1172
41026.1278
41126.1384
41226.1490
41326.1595
41426.1700
41526.1805
41626.1909
41726.2014
41826.2118
41926.2221
42026.2325
42126.2428
42226.2531
42326.2634
42426.2737
42526.2839
42626.2941
42726.3043
42826.3144
42926.3246
43026.3347
43126.3448
43226.3548
43326.3649
43426.3749
43526.3849
43626.3949
43726.4048
43826.4147
43926.4246
44026.4345
44126.4444
44226.4542
44326.4640
44426.4738
44526.4836
44626.4933
44726.5031
44826.5128
44926.5225
45026.5321
45126.5418
45226.5514
45326.5610
45426.5706
45526.5801
45626.5896
45726.5992
45826.6087
45926.6181
46026.6276
46126.6370
46226.6464
46326.6558
46426.6652
46526.6745
46626.6839
46726.6932
46826.7025
46926.7117
47026.7210
47126.7302
47226.7394
47326.7486
47426.7578
47526.7669
47626.7761
47726.7852
47826.7943
47926.8034
48026.8124
48126.8215
48226.8305
48326.8395
48426.8485
48526.8574
48626.8664
48726.8753
48826.8842
48926.8931
49026.9020
49126.9108
49226.9197
49326.9285
49426.9373
49526.9461
49626.9548
49726.9636
49826.9723
49926.9810
50026.9897
50126.9984
50227.0070
50327.0157
50427.0243
50527.0329
50627.0415
50727.0501
50827.0586
50927.0672
51027.0757
51127.0842
51227.0927
51327.1012
51427.1096
51527.1181
51627.1265
51727.1349
51827.1433
51927.1517
52027.1600
52127.1684
52227.1767
52327.1850
52427.1933
52527.2016
52627.2099
52727.2181
52827.2263
52927.2346
53027.2428
53127.2509
53227.2591
53327.2673
53427.2754
53527.2835
53627.2916
53727.2997
53827.3078
53927.3159
54027.3239
54127.3320
54227.3400
54327.3480
54427.3560
54527.3640
54627.3719
54727.3799
54827.3878
54927.3957
55027.4036
55127.4115
55227.4194
55327.4273
55427.4351
55527.4429
55627.4507
55727.4586
55827.4663
55927.4741
56027.4819
56127.4896
56227.4974
56327.5051
56427.5128
56527.5205
56627.5282
56727.5358
56827.5435
56927.5511
57027.5587
57127.5664
57227.5740
57327.5815
57427.5891
57527.5967
57627.6042
57727.6118
57827.6193
57927.6268
58027.6343
58127.6418
58227.6492
58327.6567
58427.6641
58527.6716
58627.6790
58727.6864
58827.6938
58927.7012
59027.7085
59127.7159
59227.7232
59327.7305
59427.7379
59527.7452
59627.7525
59727.7597
59827.7670
59927.7743
60027.7815
60127.7887
60227.7960
60327.8032
60427.8104
60527.8176
60627.8247
60727.8319
60827.8390
60927.8462
61027.8533
61127.8604
61227.8675
61327.8746
61427.8817
61527.8888
61627.8958
61727.9029
61827.9099
61927.9169
62027.9239
62127.9309
62227.9379
62327.9449
62427.9518
62527.9588
62627.9657
62727.9727
62827.9796
62927.9865
63027.9934
63128.0003
63228.0072
63328.0140
63428.0209
63528.0277
63628.0346
63728.0414
63828.0482
63928.0550
64028.0618
64128.0686
64228.0754
64328.0821
64428.0889
64528.0956
64628.1023
64728.1090
64828.1158
64928.1224
65028.1291
65128.1358
65228.1425
65328.1491
65428.1558
65528.1624
65628.1690
65728.1757
65828.1823
65928.1889
66028.1954
66128.2020
66228.2086
66328.2151
66428.2217
66528.2282
66628.2347
66728.2413
66828.2478
66928.2543
67028.2607
67128.2672
67228.2737
67328.2802
67428.2866
67528.2930
67628.2995
67728.3059
67828.3123
67928.3187
68028.3251
68128.3315
68228.3378
68328.3442
68428.3506
68528.3569
68628.3632
68728.3696
68828.3759
68928.3822
69028.3885
69128.3948
69228.4011
69328.4073
69428.4136
69528.4198
69628.4261
69728.4323
69828.4386
69928.4448
70028.4510
70128.4572
70228.4634
70328.4696
70428.4757
70528.4819
70628.4880
70728.4942
70828.5003
70928.5065
71028.5126
71128.5187
71228.5248
71328.5309
71428.5370
71528.5431
71628.5491
71728.5552
71828.5612
71928.5673
72028.5733
72128.5794
72228.5854
72328.5914
72428.5974
72528.6034
72628.6094
72728.6153
72828.6213
72928.6273
73028.6332
73128.6392
73228.6451
73328.6510
73428.6570
73528.6629
73628.6688
73728.6747
73828.6806
73928.6864
74028.6923
74128.6982
74228.7040
74328.7099
74428.7157
74528.7216
74628.7274
74728.7332
74828.7390
74928.7448
75028.7506
75128.7564
75228.7622
75328.7679
75428.7737
75528.7795
75628.7852
75728.7910
75828.7967
75928.8024
76028.8081
76128.8138
76228.8195
76328.8252
76428.8309
76528.8366
76628.8423
76728.8480
76828.8536
76928.8593
77028.8649
77128.8705
77228.8762
77328.8818
77428.8874
77528.8930
77628.8986
77728.9042
77828.9098
77928.9154
78028.9209
78128.9265
78228.9321
78328.9376
78428.9432
78528.9487
78628.9542
78728.9597
78828.9653
78928.9708
79028.9763
79128.9818
79228.9873
79328.9927
79428.9982
79529.0037
79629.0091
79729.0146
79829.0200
79929.0255
80029.0309
80129.0363
80229.0417
80329.0472
80429.0526
80529.0580
80629.0634
80729.0687
80829.0741
80929.0795
81029.0849
81129.0902
81229.0956
81329.1009
81429.1062
81529.1116
81629.1169
81729.1222
81829.1275
81929.1328
82029.1381
82129.1434
82229.1487
82329.1540
82429.1593
82529.1645
82629.1698
82729.1751
82829.1803
82929.1855
83029.1908
83129.1960
83229.2012
83329.2065
83429.2117
83529.2169
83629.2221
83729.2273
83829.2324
83929.2376
84029.2428
84129.2480
84229.2531
84329.2583
84429.2634
84529.2686
84629.2737
84729.2788
84829.2840
84929.2891
85029.2942
85129.2993
85229.3044
85329.3095
85429.3146
85529.3197
85629.3247
85729.3298
85829.3349
85929.3399
86029.3450
86129.3500
86229.3551
86329.3601
86429.3651
86529.3702
86629.3752
86729.3802
86829.3852
86929.3902
87029.3952
87129.4002
87229.4052
87329.4101
87429.4151
87529.4201
87629.4250
87729.4300
87829.4349
87929.4399
88029.4448
88129.4498
88229.4547
88329.4596
88429.4645
88529.4694
88629.4743
88729.4792
88829.4841
88929.4890
89029.4939
89129.4988
89229.5036
89329.5085
89429.5134
89529.5182
89629.5231
89729.5279
89829.5328
89929.5376
90029.5424
90129.5472
90229.5521
90329.5569
90429.5617
90529.5665
90629.5713
90729.5761
90829.5809
90929.5856
91029.5904
91129.5952
91229.5999
91329.6047
91429.6095
91529.6142
91629.6190
91729.6237
91829.6284
91929.6332
92029.6379
92129.6426
92229.6473
92329.6520
92429.6567
92529.6614
92629.6661
92729.6708
92829.6755
92929.6802
93029.6848
93129.6895
93229.6942
93329.6988
93429.7035
93529.7081
93629.7128
93729.7174
93829.7220
93929.7267
94029.7313
94129.7359
94229.7405
94329.7451
94429.7497
94529.7543
94629.7589
94729.7635
94829.7681
94929.7727
95029.7772
95129.7818
95229.7864
95329.7909
95429.7955
95529.8000
95629.8046
95729.8091
95829.8137
95929.8182
96029.8227
96129.8272
96229.8318
96329.8363
96429.8408
96529.8453
96629.8498
96729.8543
96829.8588
96929.8632
97029.8677
97129.8722
97229.8767
97329.8811
97429.8856
97529.8900
97629.8945
97729.8989
97829.9034
97929.9078
98029.9123
98129.9167
98229.9211
98329.9255
98429.9300
98529.9344
98629.9388
98729.9432
98829.9476
98929.9520
99029.9564
99129.9607
99229.9651
99329.9695
99429.9739
99529.9782
99629.9826
99729.9870
99829.9913
99929.9957
100030.0000