This converter turns torr into atmospheres instantly, using the exact factor 1 torr = 0.001315789474 atmospheres. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
One millimetre of mercury, used in vacuum work. Standard atmospheric pressure by definition — 101,325 pascals exactly.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
torr- The amount you are converting, measured in torr
0.001315789474- The exact number of atmospheres in one torr
atmospheres- The converted result
How it works, step by step
- Enter the number of torr you want to convert.
- The value is multiplied by 0.001315789474, the exact conversion factor.
- The result is displayed in atmospheres, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 torr
Multiply 5 by 0.0013157895. That gives 0.006579 atmospheres. A quick sanity check: one torr is smaller than one atmosphere, so the number should get smaller — and it does.
Converting 72 torr
72 × 0.0013157895 = 0.094737 atmospheres. Working backwards, 0.094737 ÷ 0.0013157895 returns 72 torr, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many atmospheres are in one torr?
Exactly 0.001315789474. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert torr to atmospheres?
Atmospheres = torr × 0.001315789474. To reverse it, divide instead: torr = atmospheres ÷ 0.001315789474, which is the same as multiplying by 760.
Is the torr bigger than the atmosphere?
No. One torr is only 0.00131579 of a atmosphere, so the atmosphere is the larger unit.
Why does my answer differ slightly from other torr to atmospheres converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a torr?
One millimetre of mercury, used in vacuum work.
What is a atmosphere?
Standard atmospheric pressure by definition — 101,325 pascals exactly.
Torr to atmospheres reference table
| Torr | Atmospheres |
|---|---|
| 0.5 Torr | 0.000658 atm |
| 1 Torr | 0.001316 atm |
| 2 Torr | 0.002632 atm |
| 3 Torr | 0.003947 atm |
| 5 Torr | 0.006579 atm |
| 10 Torr | 0.013158 atm |
| 15 Torr | 0.019737 atm |
| 20 Torr | 0.026316 atm |
| 25 Torr | 0.032895 atm |
| 50 Torr | 0.065789 atm |
| 75 Torr | 0.098684 atm |
| 100 Torr | 0.131579 atm |
| 250 Torr | 0.328947 atm |
| 500 Torr | 0.657895 atm |
| 1000 Torr | 1.3158 atm |
Exact factor: 1 torr = 0.001315789474 atmospheres. Values rounded for display.