Atmosphere to Millibar Pressure Converter
Convert Atmosphere (atm) to Millibar (mbar) with this free calculator. Type a value, press Convert, and the page applies the same factor shown in the formula below — no rounded shortcut, and nothing is stored on a server.
Millibar to Atmosphere (mbar to atm) ►
How to convert Atmosphere to Millibar
1 atm = 101,325 Pa
1 mbar = 100 Pa
1 atmosphere (atm) is equal to 1013.25 millibar (mbar).
mbar = atm × 1013.25
Multiply the pressure in atmospheres by 1013.25:
Example: Convert 1 atm to mbar:
mbar = 1 × 1013.25 = 1013.25 mbar
What is a Atmosphere?
The Atmosphere (atm) is the starting or target unit on this page. Use the calculator above to convert values without looking up the factor by hand.
What is a Millibar?
The Millibar (mbar) is the starting or target unit on this page. Use the calculator above to convert values without looking up the factor by hand.
This page converts pressure from Atmosphere into Millibar. One atm equals 1013.25 mbar.
Atmosphere to Millibar conversion table
Common atm values and the matching mbar result, calculated with the same factor as the widget. Highlight a nearby row if you want a quick check without entering a number.
| Atmosphere (atm) | Millibar (mbar) |
|---|---|
| 0.5 atm | 506.625 mbar |
| 1 atm | 1013.25 mbar |
| 2 atm | 2026.5 mbar |
| 5 atm | 5066.25 mbar |
| 10 atm | 10132.5 mbar |
| 100 atm | 101325 mbar |
How this calculator works
The form on this page is a Atmosphere-to-Millibar converter. After you enter a number, JavaScript multiplies or rearranges it with the published conversion factor and writes the mbar result in the output box. The step-by-step panel repeats the arithmetic so you can copy it into homework or a spreadsheet.
Reviewed by Hamsen, founder of GigaTables and a biology engineer. See the about page for how formulas are checked before a tool is published.
FAQ
How many mbar are in 1 atm?
1 atm = 1013.25 mbar.
How do I convert Atmosphere to Millibar?
Multiply the pressure in atmospheres by 1013.25:
Is this atm to mbar converter free?
Yes. GigaTables calculators are free to use in a browser. You do not need an account, and the values you type are not uploaded.