Pressure • NIST Exact

Millibars Atmospheres

mbar → atm

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Millibars to Atmospheres Formula

To convert from Millibars to Atmospheres, you can use the following formula:

Atmospheres = Millibars × NaN

This means you need to multiply your Millibars value by NaN to get the equivalent value in Atmospheres.

mbar → atm Reference Table

mbar atm
0.001 mbar 9.869232667e-7 atm
0.002 mbar 0.000001973846533 atm
0.003 mbar 0.0000029607698 atm
0.004 mbar 0.000003947693067 atm
0.005 mbar 0.000004934616334 atm
0.006 mbar 0.0000059215396 atm
0.007 mbar 0.000006908462867 atm
0.008 mbar 0.000007895386134 atm
0.009 mbar 0.0000088823094 atm
0.01 mbar 0.000009869232667 atm
0.02 mbar 0.00001973846533 atm
0.03 mbar 0.000029607698 atm
0.04 mbar 0.00003947693067 atm
0.05 mbar 0.00004934616334 atm
0.06 mbar 0.000059215396 atm
0.07 mbar 0.00006908462867 atm
0.08 mbar 0.00007895386134 atm
0.09 mbar 0.000088823094 atm
0.1 mbar 0.00009869232667 atm
0.2 mbar 0.0001973846533 atm
0.3 mbar 0.00029607698 atm
0.4 mbar 0.0003947693067 atm
0.5 mbar 0.0004934616334 atm
0.6 mbar 0.00059215396 atm
0.7 mbar 0.0006908462867 atm
0.8 mbar 0.0007895386134 atm
0.9 mbar 0.00088823094 atm
1 mbar 0.0009869232667 atm
1.5 mbar 0.0014803849 atm
2 mbar 0.001973846533 atm
2.5 mbar 0.002467308167 atm
3 mbar 0.0029607698 atm
3.5 mbar 0.003454231434 atm
4 mbar 0.003947693067 atm
4.5 mbar 0.0044411547 atm
5 mbar 0.004934616334 atm
5.5 mbar 0.005428077967 atm
6 mbar 0.0059215396 atm
6.5 mbar 0.006415001234 atm
7 mbar 0.006908462867 atm
7.5 mbar 0.0074019245 atm
8 mbar 0.007895386134 atm
8.5 mbar 0.008388847767 atm
9 mbar 0.0088823094 atm
9.5 mbar 0.009375771034 atm
10 mbar 0.009869232667 atm
11 mbar 0.01085615593 atm
12 mbar 0.0118430792 atm
13 mbar 0.01283000247 atm
14 mbar 0.01381692573 atm
15 mbar 0.014803849 atm
16 mbar 0.01579077227 atm
17 mbar 0.01677769553 atm
18 mbar 0.0177646188 atm
19 mbar 0.01875154207 atm
20 mbar 0.01973846533 atm
25 mbar 0.02467308167 atm
30 mbar 0.029607698 atm
35 mbar 0.03454231434 atm
40 mbar 0.03947693067 atm
45 mbar 0.044411547 atm
50 mbar 0.04934616334 atm
55 mbar 0.05428077967 atm
60 mbar 0.059215396 atm
65 mbar 0.06415001234 atm
70 mbar 0.06908462867 atm
75 mbar 0.074019245 atm
80 mbar 0.07895386134 atm
85 mbar 0.08388847767 atm
90 mbar 0.088823094 atm
95 mbar 0.09375771034 atm
100 mbar 0.09869232667 atm
120 mbar 0.118430792 atm
125 mbar 0.1233654083 atm
130 mbar 0.1283000247 atm
140 mbar 0.1381692573 atm
150 mbar 0.14803849 atm
160 mbar 0.1579077227 atm
175 mbar 0.1727115717 atm
180 mbar 0.177646188 atm
200 mbar 0.1973846533 atm
225 mbar 0.222057735 atm
250 mbar 0.2467308167 atm
275 mbar 0.2714038983 atm
300 mbar 0.29607698 atm
350 mbar 0.3454231434 atm
400 mbar 0.3947693067 atm
450 mbar 0.44411547 atm
500 mbar 0.4934616334 atm
600 mbar 0.59215396 atm
700 mbar 0.6908462867 atm
750 mbar 0.74019245 atm
800 mbar 0.7895386134 atm
900 mbar 0.88823094 atm
1000 mbar 0.9869232667 atm
1200 mbar 1.18430792 atm
1250 mbar 1.233654083 atm
1500 mbar 1.4803849 atm
1750 mbar 1.727115717 atm
2000 mbar 1.973846533 atm
2500 mbar 2.467308167 atm
3000 mbar 2.9607698 atm
4000 mbar 3.947693067 atm
4500 mbar 4.4411547 atm
5000 mbar 4.934616334 atm
6000 mbar 5.9215396 atm
7000 mbar 6.908462867 atm
7500 mbar 7.4019245 atm
8000 mbar 7.895386134 atm
9000 mbar 8.8823094 atm
10000 mbar 9.869232667 atm
15000 mbar 14.803849 atm
20000 mbar 19.73846533 atm
25000 mbar 24.67308167 atm
50000 mbar 49.34616334 atm
75000 mbar 74.019245 atm
100000 mbar 98.69232667 atm

Values based on NIST SP 811 conversion factors

Why Convert Millibars to Atmospheres?

Converting between millibars (mbar) and atmospheres (atm) is one of the most common pressure conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert mbar to atm saves time and prevents errors.

Pressure conversions between mbar and atm are vital in automotive maintenance, meteorology, and scuba diving. Tire pressure affects fuel efficiency and safety, requiring drivers to convert between PSI and bar depending on the gauge used. Divers must strictly monitor pressure to avoid decompression sickness, often needing to convert depth and tank pressure readings. In weather forecasting, atmospheric pressure changes indicate approaching storms, with data often shared in different units globally. Failing to convert pressure accurately can lead to equipment failure, tire blowouts, or life-threatening situations underwater.

How to Convert Millibars to Atmospheres

To convert millibars to atmospheres, use the following formula:

atm = mbar × 0.0009869232667

Example: 1 mbar = 0.0009869232667 atm

For example, 5 mbar = 0.004934616334 atm, 10 mbar = 0.009869232667 atm, and 100 mbar = 0.09869232667 atm. For larger values, 1000 mbar = 0.9869232667 atm. Conversely, 1 atm = 1013.25 mbar. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Mistakes to Avoid

  • Gauge vs Absolute: confusing gauge pressure (psig) with absolute pressure (psia).
  • Bar vs Pascal: 1 Bar is 100,000 Pascals, not 10 or 100.
  • Atmosphere variations: confusing standard atm with technical atm.

Pro Tips

  • Tire checks: Check tire pressure when cold (tires heat up and pressure rises while driving).
  • PSI rule: Typical car tires are 30-35 PSI.
  • Altitude effect: Air pressure drops as you go higher (ears popping).

What is a Millibar?

A metric unit of pressure equal to 100 Pascals.

Traditionally used in meteorology.

What is a Atmosphere?

Standard atmosphere (atm), defined as 101,325 Pascals.

Reference pressure for sea level.

Frequently Asked Questions

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