Altitude to Pressure Conversion Table

Convert an altitude in feet or metres of height above sea level to a pressure reading in millibar (mbar, mb or mbr), pounds per square inch (psi), millimetres of mercury at zero degrees celsius (mmHg @ 0 deg C) or inches of mercury at zero degrees celsius (inHg @ 0 deg C).

ft	m	mbar	psi	mmHg	inHg
-5000	-1524.0	1210.23	17.553	907.75	35.738
-4000	-1219.2	1168.55	16.948	876.48	34.507
-3000	-914.40	1128.03	16.361	846.09	33.311
-2000	-609.60	1088.66	15.790	816.56	32.148
-1000	-304.80	1050.41	15.235	787.87	31.018
-900	-274.32	1046.64	15.180	785.05	30.907
-800	-243.84	1042.89	15.126	782.23	30.796
-700	-213.36	1039.15	15.072	779.42	30.686
-600	-182.88	1035.41	15.017	776.62	30.576
-500	-152.40	1031.69	14.963	773.83	30.466
-400	-121.92	1027.98	14.910	771.05	30.356
-300	-91.440	1024.28	14.856	768.28	30.247
-200	-60.960	1020.59	14.802	765.51	30.138
-100	-30.480	1016.92	14.749	762.75	30.030
-50	-15.240	1015.08	14.723	761.37	29.975
0	0	1013.25	14.696	760.00	29.921
50	15.240	1011.42	14.669	758.63	29.867
100	30.480	1009.59	14.643	757.26	29.813
200	60.960	1005.95	14.590	754.52	29.706
300	91.440	1002.31	14.537	751.80	29.598
400	121.92	998.689	14.485	749.08	29.491
500	152.40	995.075	14.432	746.37	29.385
600	182.88	991.472	14.380	743.67	29.278
700	213.36	987.880	14.328	740.97	29.172
800	243.84	984.298	14.276	738.28	29.066
900	274.32	980.727	14.224	735.61	28.961
1000	304.80	977.166	14.173	732.93	28.856
2000	609.60	942.129	13.664	706.65	27.821
3000	914.40	908.117	13.171	681.14	26.817
4000	1219.2	875.105	12.692	656.38	25.842
5000	1524.0	843.073	12.228	632.36	24.896
6000	1828.8	811.996	11.777	609.05	23.978
7000	2133.6	781.854	11.340	586.44	23.088
8000	2438.4	752.624	10.916	564.51	22.225
9000	2743.2	724.285	10.505	543.26	21.388
10000	3048.0	696.817	10.106	522.66	20.577
15000	4572.0	571.820	8.2935	428.90	16.886
20000	6096.0	465.633	6.7534	349.25	13.750
25000	7620.0	376.009	5.4536	282.03	11.104
30000	9144.0	300.896	4.3641	225.69	8.8855
35000	10668	238.423	3.4580	178.83	7.0406
40000	12192	187.54	2.7200	140.67	5.5381
45000	13716	147.48	2.1390	110.62	4.3550
50000	15240	115.97	1.6821	86.987	3.4247
55000	16764	91.199	1.3227	68.405	2.6931
60000	18288	71.717	1.0402	53.792	2.1178
65000	19812	56.397	0.8180	42.301	1.6654
70000	21336	44.377	0.6436	33.286	1.3105
75000	22860	34.978	0.5073	26.236	1.0329
80000	24384	27.615	0.4005	20.713	0.8155
85000	25908	21.837	0.3167	16.379	0.6448
90000	27432	17.296	0.2509	12.973	0.5107
95000	28956	13.721	0.1990	10.291	0.4052
100000	30480	10.902	0.1581	8.1769	0.3219

The height relative to sea level conversions are derived using the US Standard Atmosphere 1976 barometric formula for geopotential altitude with the following values[1-6] at heights from 5,000 ft (1524 m) below to 100,000 ft (30,480 m) above mean sea level.

1. Standard atmospheric pressure of 1013.25 mb at 0 m, 226.321 mb at 11,000 m, 54.7489 mb at 20,000 m above mean sea level.
2. Standard temperature of 288.15K (15°C) at 0 m, 216.65K (-56.5°C) at 11,000 m and 20,000 m above mean sea level.
3. Standard thermal gradient or lapse rate of -0.0065 K/m from 0 to 11,000 m, 0 K/m from 11,000 to 20,000 m, 0.001 k/m from 20,000 to 32,000 m above mean sea level.
4. Standard acceleration due to gravity of 9.80665 m/s².
5. Gas constant for air of 8.31432 J/Kmol K.
6. Molar mass of air of 0.0289644 kg/mole.

n.b. Please note that the calculated altitude values are not absolute precise conversions and should not be treated as such.