The energy of a photon is:
Where h is the Planck constant, and c is the speed of light. Note that x-ray energies are usually reported in electron-volts (1 J = 6.2415096471204×15 keV).
Lookup tables
Far Infrared
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
1.24 meV
|
999.873 µm
|
|
1.96 meV
|
634.075 µm
|
|
3.08 meV
|
402.102 µm
|
|
4.86 meV
|
254.996 µm
|
|
7.67 meV
|
161.707 µm
|
1.26 meV
|
980.267 µm
|
|
1.99 meV
|
621.642 µm
|
|
3.15 meV
|
394.218 µm
|
|
4.96 meV
|
249.996 µm
|
|
7.82 meV
|
158.536 µm
|
1.29 meV
|
961.046 µm
|
|
2.03 meV
|
609.453 µm
|
|
3.21 meV
|
386.488 µm
|
|
5.06 meV
|
245.094 µm
|
|
7.98 meV
|
155.428 µm
|
1.32 meV
|
942.202 µm
|
|
2.08 meV
|
597.503 µm
|
|
3.27 meV
|
378.910 µm
|
|
5.16 meV
|
240.288 µm
|
|
8.14 meV
|
152.380 µm
|
1.34 meV
|
923.728 µm
|
|
2.12 meV
|
585.787 µm
|
|
3.34 meV
|
371.481 µm
|
|
5.26 meV
|
235.577 µm
|
|
8.30 meV
|
149.392 µm
|
1.37 meV
|
905.615 µm
|
|
2.16 meV
|
574.301 µm
|
|
3.40 meV
|
364.197 µm
|
|
5.37 meV
|
230.957 µm
|
|
8.47 meV
|
146.463 µm
|
1.40 meV
|
887.858 µm
|
|
2.20 meV
|
563.041 µm
|
|
3.47 meV
|
357.055 µm
|
|
5.48 meV
|
226.429 µm
|
|
8.63 meV
|
143.591 µm
|
1.42 meV
|
870.449 µm
|
|
2.25 meV
|
552.001 µm
|
|
3.54 meV
|
350.054 µm
|
|
5.59 meV
|
221.989 µm
|
|
8.81 meV
|
140.776 µm
|
1.45 meV
|
853.382 µm
|
|
2.29 meV
|
541.177 µm
|
|
3.61 meV
|
343.191 µm
|
|
5.70 meV
|
217.636 µm
|
|
8.98 meV
|
138.015 µm
|
1.48 meV
|
836.649 µm
|
|
2.34 meV
|
530.566 µm
|
|
3.68 meV
|
336.461 µm
|
|
5.81 meV
|
213.369 µm
|
|
9.16 meV
|
135.309 µm
|
1.51 meV
|
820.244 µm
|
|
2.38 meV
|
520.162 µm
|
|
3.76 meV
|
329.864 µm
|
|
5.93 meV
|
209.185 µm
|
|
9.35 meV
|
132.656 µm
|
1.54 meV
|
804.161 µm
|
|
2.43 meV
|
509.963 µm
|
|
3.83 meV
|
323.396 µm
|
|
6.05 meV
|
205.084 µm
|
|
9.53 meV
|
130.055 µm
|
1.57 meV
|
788.393 µm
|
|
2.48 meV
|
499.964 µm
|
|
3.91 meV
|
317.055 µm
|
|
6.17 meV
|
201.062 µm
|
|
9.72 meV
|
127.505 µm
|
1.60 meV
|
772.934 µm
|
|
2.53 meV
|
490.161 µm
|
|
3.99 meV
|
310.838 µm
|
|
6.29 meV
|
197.120 µm
|
|
9.92 meV
|
125.005 µm
|
1.64 meV
|
757.778 µm
|
|
2.58 meV
|
480.550 µm
|
|
4.07 meV
|
304.743 µm
|
|
6.42 meV
|
193.255 µm
|
|
10.12 meV
|
122.554 µm
|
1.67 meV
|
742.920 µm
|
|
2.63 meV
|
471.127 µm
|
|
4.15 meV
|
298.768 µm
|
|
6.54 meV
|
189.466 µm
|
|
10.32 meV
|
120.151 µm
|
1.70 meV
|
728.353 µm
|
|
2.68 meV
|
461.889 µm
|
|
4.23 meV
|
292.910 µm
|
|
6.67 meV
|
185.751 µm
|
|
10.53 meV
|
117.795 µm
|
1.74 meV
|
714.072 µm
|
|
2.74 meV
|
452.833 µm
|
|
4.32 meV
|
287.167 µm
|
|
6.81 meV
|
182.108 µm
|
|
10.74 meV
|
115.485 µm
|
1.77 meV
|
700.070 µm
|
|
2.79 meV
|
443.954 µm
|
|
4.40 meV
|
281.536 µm
|
|
6.94 meV
|
178.538 µm
|
|
10.95 meV
|
113.221 µm
|
1.81 meV
|
686.343 µm
|
|
2.85 meV
|
435.249 µm
|
|
4.49 meV
|
276.016 µm
|
|
7.08 meV
|
175.037 µm
|
|
11.17 meV
|
111.001 µm
|
1.84 meV
|
672.886 µm
|
|
2.91 meV
|
426.714 µm
|
|
4.58 meV
|
270.603 µm
|
|
7.22 meV
|
171.605 µm
|
|
11.39 meV
|
108.824 µm
|
1.88 meV
|
659.692 µm
|
|
2.96 meV
|
418.347 µm
|
|
4.67 meV
|
265.297 µm
|
|
7.37 meV
|
168.240 µm
|
|
11.62 meV
|
106.690 µm
|
1.92 meV
|
646.757 µm
|
|
3.02 meV
|
410.145 µm
|
|
4.77 meV
|
260.096 µm
|
|
7.52 meV
|
164.941 µm
|
|
11.85 meV
|
104.598 µm
|
Mid Infrared
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
12.40 meV
|
99.987 µm
|
|
19.55 meV
|
63.408 µm
|
|
30.83 meV
|
40.210 µm
|
|
48.62 meV
|
25.500 µm
|
|
76.67 meV
|
16.171 µm
|
12.65 meV
|
98.027 µm
|
|
19.94 meV
|
62.164 µm
|
|
31.45 meV
|
39.422 µm
|
|
49.59 meV
|
25.000 µm
|
|
78.21 meV
|
15.854 µm
|
12.90 meV
|
96.105 µm
|
|
20.34 meV
|
60.945 µm
|
|
32.08 meV
|
38.649 µm
|
|
50.59 meV
|
24.509 µm
|
|
79.77 meV
|
15.543 µm
|
13.16 meV
|
94.220 µm
|
|
20.75 meV
|
59.750 µm
|
|
32.72 meV
|
37.891 µm
|
|
51.60 meV
|
24.029 µm
|
|
81.37 meV
|
15.238 µm
|
13.42 meV
|
92.373 µm
|
|
21.17 meV
|
58.579 µm
|
|
33.38 meV
|
37.148 µm
|
|
52.63 meV
|
23.558 µm
|
|
82.99 meV
|
14.939 µm
|
13.69 meV
|
90.562 µm
|
|
21.59 meV
|
57.430 µm
|
|
34.04 meV
|
36.420 µm
|
|
53.68 meV
|
23.096 µm
|
|
84.65 meV
|
14.646 µm
|
13.96 meV
|
88.786 µm
|
|
22.02 meV
|
56.304 µm
|
|
34.72 meV
|
35.706 µm
|
|
54.76 meV
|
22.643 µm
|
|
86.35 meV
|
14.359 µm
|
14.24 meV
|
87.045 µm
|
|
22.46 meV
|
55.200 µm
|
|
35.42 meV
|
35.005 µm
|
|
55.85 meV
|
22.199 µm
|
|
88.07 meV
|
14.078 µm
|
14.53 meV
|
85.338 µm
|
|
22.91 meV
|
54.118 µm
|
|
36.13 meV
|
34.319 µm
|
|
56.97 meV
|
21.764 µm
|
|
89.83 meV
|
13.802 µm
|
14.82 meV
|
83.665 µm
|
|
23.37 meV
|
53.057 µm
|
|
36.85 meV
|
33.646 µm
|
|
58.11 meV
|
21.337 µm
|
|
91.63 meV
|
13.531 µm
|
15.12 meV
|
82.024 µm
|
|
23.84 meV
|
52.016 µm
|
|
37.59 meV
|
32.986 µm
|
|
59.27 meV
|
20.919 µm
|
|
93.46 meV
|
13.266 µm
|
15.42 meV
|
80.416 µm
|
|
24.31 meV
|
50.996 µm
|
|
38.34 meV
|
32.340 µm
|
|
60.46 meV
|
20.508 µm
|
|
95.33 meV
|
13.005 µm
|
15.73 meV
|
78.839 µm
|
|
24.80 meV
|
49.996 µm
|
|
39.10 meV
|
31.706 µm
|
|
61.66 meV
|
20.106 µm
|
|
97.24 meV
|
12.750 µm
|
16.04 meV
|
77.293 µm
|
|
25.29 meV
|
49.016 µm
|
|
39.89 meV
|
31.084 µm
|
|
62.90 meV
|
19.712 µm
|
|
99.18 meV
|
12.500 µm
|
16.36 meV
|
75.778 µm
|
|
25.80 meV
|
48.055 µm
|
|
40.68 meV
|
30.474 µm
|
|
64.16 meV
|
19.325 µm
|
|
101.17 meV
|
12.255 µm
|
16.69 meV
|
74.292 µm
|
|
26.32 meV
|
47.113 µm
|
|
41.50 meV
|
29.877 µm
|
|
65.44 meV
|
18.947 µm
|
|
103.19 meV
|
12.015 µm
|
17.02 meV
|
72.835 µm
|
|
26.84 meV
|
46.189 µm
|
|
42.33 meV
|
29.291 µm
|
|
66.75 meV
|
18.575 µm
|
|
105.25 meV
|
11.779 µm
|
17.36 meV
|
71.407 µm
|
|
27.38 meV
|
45.283 µm
|
|
43.18 meV
|
28.717 µm
|
|
68.08 meV
|
18.211 µm
|
|
107.36 meV
|
11.549 µm
|
17.71 meV
|
70.007 µm
|
|
27.93 meV
|
44.395 µm
|
|
44.04 meV
|
28.154 µm
|
|
69.44 meV
|
17.854 µm
|
|
109.51 meV
|
11.322 µm
|
18.06 meV
|
68.634 µm
|
|
28.49 meV
|
43.525 µm
|
|
44.92 meV
|
27.602 µm
|
|
70.83 meV
|
17.504 µm
|
|
111.70 meV
|
11.100 µm
|
18.43 meV
|
67.289 µm
|
|
29.06 meV
|
42.671 µm
|
|
45.82 meV
|
27.060 µm
|
|
72.25 meV
|
17.160 µm
|
|
113.93 meV
|
10.882 µm
|
18.79 meV
|
65.969 µm
|
|
29.64 meV
|
41.835 µm
|
|
46.73 meV
|
26.530 µm
|
|
73.69 meV
|
16.824 µm
|
|
116.21 meV
|
10.669 µm
|
19.17 meV
|
64.676 µm
|
|
30.23 meV
|
41.014 µm
|
|
47.67 meV
|
26.010 µm
|
|
75.17 meV
|
16.494 µm
|
|
118.53 meV
|
10.460 µm
|
Near Infrared
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
|
E
|
λ
|
1.77 eV
|
700.5 nm
|
|
1.99 eV
|
624.6 nm
|
|
2.23 eV
|
556.9 nm
|
|
2.50 eV
|
496.5 nm
|
|
2.80 eV
|
442.7 nm
|
1.78 eV
|
697.0 nm
|
|
2.00 eV
|
621.5 nm
|
|
2.24 eV
|
554.1 nm
|
|
2.51 eV
|
494.0 nm
|
|
2.81 eV
|
440.5 nm
|
1.79 eV
|
693.5 nm
|
|
2.01 eV
|
618.4 nm
|
|
2.25 eV
|
551.3 nm
|
|
2.52 eV
|
491.6 nm
|
|
2.83 eV
|
438.3 nm
|
1.80 eV
|
690.1 nm
|
|
2.02 eV
|
615.3 nm
|
|
2.26 eV
|
548.6 nm
|
|
2.53 eV
|
489.1 nm
|
|
2.84 eV
|
436.1 nm
|
1.81 eV
|
686.6 nm
|
|
2.03 eV
|
612.2 nm
|
|
2.27 eV
|
545.9 nm
|
|
2.55 eV
|
486.7 nm
|
|
2.86 eV
|
434.0 nm
|
1.81 eV
|
683.2 nm
|
|
2.04 eV
|
609.2 nm
|
|
2.28 eV
|
543.2 nm
|
|
2.56 eV
|
484.3 nm
|
|
2.87 eV
|
431.8 nm
|
1.82 eV
|
679.8 nm
|
|
2.05 eV
|
606.1 nm
|
|
2.29 eV
|
540.5 nm
|
|
2.57 eV
|
481.9 nm
|
|
2.89 eV
|
429.7 nm
|
1.83 eV
|
676.4 nm
|
|
2.06 eV
|
603.1 nm
|
|
2.31 eV
|
537.8 nm
|
|
2.59 eV
|
479.5 nm
|
|
2.90 eV
|
427.5 nm
|
1.84 eV
|
673.1 nm
|
|
2.07 eV
|
600.1 nm
|
|
2.32 eV
|
535.1 nm
|
|
2.60 eV
|
477.1 nm
|
|
2.91 eV
|
425.4 nm
|
1.85 eV
|
669.7 nm
|
|
2.08 eV
|
597.1 nm
|
|
2.33 eV
|
532.4 nm
|
|
2.61 eV
|
474.7 nm
|
|
2.93 eV
|
423.3 nm
|
1.86 eV
|
666.4 nm
|
|
2.09 eV
|
594.2 nm
|
|
2.34 eV
|
529.8 nm
|
|
2.62 eV
|
472.4 nm
|
|
2.94 eV
|
421.2 nm
|
1.87 eV
|
663.1 nm
|
|
2.10 eV
|
591.2 nm
|
|
2.35 eV
|
527.1 nm
|
|
2.64 eV
|
470.0 nm
|
|
2.96 eV
|
419.1 nm
|
1.88 eV
|
659.8 nm
|
|
2.11 eV
|
588.3 nm
|
|
2.36 eV
|
524.5 nm
|
|
2.65 eV
|
467.7 nm
|
|
2.97 eV
|
417.0 nm
|
1.89 eV
|
656.5 nm
|
|
2.12 eV
|
585.3 nm
|
|
2.38 eV
|
521.9 nm
|
|
2.66 eV
|
465.3 nm
|
|
2.99 eV
|
414.9 nm
|
1.90 eV
|
653.2 nm
|
|
2.13 eV
|
582.4 nm
|
|
2.39 eV
|
519.3 nm
|
|
2.68 eV
|
463.0 nm
|
|
3.00 eV
|
412.8 nm
|
1.91 eV
|
650.0 nm
|
|
2.14 eV
|
579.5 nm
|
|
2.40 eV
|
516.7 nm
|
|
2.69 eV
|
460.7 nm
|
|
3.02 eV
|
410.8 nm
|
1.92 eV
|
646.7 nm
|
|
2.15 eV
|
576.7 nm
|
|
2.41 eV
|
514.2 nm
|
|
2.70 eV
|
458.4 nm
|
|
3.03 eV
|
408.8 nm
|
1.93 eV
|
643.5 nm
|
|
2.16 eV
|
573.8 nm
|
|
2.42 eV
|
511.6 nm
|
|
2.72 eV
|
456.2 nm
|
|
3.05 eV
|
406.7 nm
|
1.94 eV
|
640.3 nm
|
|
2.17 eV
|
570.9 nm
|
|
2.44 eV
|
509.1 nm
|
|
2.73 eV
|
453.9 nm
|
|
3.06 eV
|
404.7 nm
|
1.95 eV
|
637.1 nm
|
|
2.18 eV
|
568.1 nm
|
|
2.45 eV
|
506.5 nm
|
|
2.75 eV
|
451.6 nm
|
|
3.08 eV
|
402.7 nm
|
1.96 eV
|
634.0 nm
|
|
2.19 eV
|
565.3 nm
|
|
2.46 eV
|
504.0 nm
|
|
2.76 eV
|
449.4 nm
|
|
3.09 eV
|
400.7 nm
|
1.97 eV
|
630.8 nm
|
|
2.20 eV
|
562.5 nm
|
|
2.47 eV
|
501.5 nm
|
|
2.77 eV
|
447.1 nm
|
|
3.11 eV
|
398.7 nm
|
1.98 eV
|
627.7 nm
|
|
2.22 eV
|
559.7 nm
|
|
2.48 eV
|
499.0 nm
|
|
2.79 eV
|
444.9 nm
|
|
3.13 eV
|
396.7 nm
|
Near Ultraviolet
Extreme Ultraviolet
Soft X-rays
Hard X-rays
Gamma rays