100 atm to bar — 100 standard atmospheres in bar
Exact 100 × 1.01325 = 101.325
100 standard atmospheres in other units
| Pascals | 10,132,500 | Pa |
|---|---|---|
| Hectopascals | 101,325 | hPa |
| Kilopascals | 10,132.5 | kPa |
| Megapascals | 10.1325 | MPa |
| Millibars | 101,325 | mbar |
| Bar | 101.325 | bar |
| Pounds per square inch | 1,469.59 | psi |
| Torr | 76,000 | Torr |
| Millimetres of mercury | 75,999.99 | mmHg |
| Inches of mercury | 2,992.13 | inHg |
atm to bar at a glance
| Standard atmospheres | Bar |
|---|---|
| 1 atm | 1.01325 bar |
| 2 atm | 2.0265 bar |
| 3 atm | 3.03975 bar |
| 5 atm | 5.06625 bar |
| 10 atm | 10.1325 bar |
| 20 atm | 20.265 bar |
| 25 atm | 25.33125 bar |
| 50 atm | 50.6625 bar |
| 100 atm | 101.325 bar |
| 250 atm | 253.3125 bar |
| 500 atm | 506.625 bar |
| 1,000 atm | 1,013.25 bar |
How to convert standard atmospheres to bar
Multiply by 1.01325 — one standard atmosphere is 1.01325 bar. That factor is exact: it comes from the definition of the units rather than from a measurement, so it will not change and does not need rounding.
Working 100 × 1.01325 = 101.325
In words: about one hundred one bar.
What these units are
The standard atmosphere and the bar are covered in the pressure unit guide, along with every other unit on this page.
Questions
How many bar are in a standard atmosphere?
One standard atmosphere is 1.01325 bar. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 100 standard atmospheres in bar?
100 standard atmospheres is 101.325 bar. The working is 100 × 1.01325 = 101.325.
What pressure should my tyres be?
Look at the sticker in the driver's door frame or the fuel flap, not the number moulded into the tyre — that one is the tyre's maximum, not the manufacturer's recommendation. Most cars sit somewhere around 32 to 35 psi, which is roughly 2.2 to 2.4 bar.
Is my tyre gauge measuring absolute or gauge pressure?
Gauge pressure — the amount above the surrounding air. A tyre reading 32 psi actually contains about 46.7 psi absolute, because atmospheric pressure of roughly 14.7 psi is already pressing on the other side of the gauge. Conversions on this page are between units, and leave that distinction alone.
Why do weather forecasts use hectopascals and millibars interchangeably?
Because they are the same size. One hectopascal is exactly one millibar, so the change from mbar to hPa was a relabelling rather than a conversion. Standard sea-level pressure is 1013.25 of either.
What is the difference between torr and mmHg?
Almost nothing, and the difference is deliberate. A torr is exactly one seven-hundred-and-sixtieth of a standard atmosphere; the conventional mmHg is defined as exactly 133.322387415 pascals. They diverge by about one part in seven million — invisible in medicine, occasionally not in vacuum work.