Convert Torr to Standard atmosphere
1 torr = 0.001315789 standard atmosphere (atm). For example, 10 torr = 0.01315789 standard atmosphere and 100 torr = 0.1315789 standard atmosphere. Type any value below to convert torr to standard atmosphere both ways — it runs entirely in your browser.
Quick answer: Torr to Standard atmosphere
1 Torr = 0.001315789 Standard atmosphere (Torr → atm). To convert torr to standard atmosphere, multiply by 0.001315789. To convert standard atmosphere to torr, multiply by 760. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common torr-to-standard atmosphere questions.
How to convert Torr to Standard atmosphere
To convert torr to standard atmosphere, multiply the number of torr by the conversion factor 0.001315789, because 1 Torr = 0.001315789 atm. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 atm = 760 Torr, so you divide by 0.001315789 (or multiply by 760) to turn standard atmosphere back into torr.
atm = Torr × 0.001315789 ·
Torr = atm × 760
- Write down the value you want to convert, in torr.
- Multiply it by 0.001315789.
- The result is the same area/length/quantity expressed in standard atmosphere.
Torr to Standard atmosphere — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 torr is 0.006578947 standard atmosphere because 5 Torr × 0.001315789 = 0.006578947 atm.
| Torr | Calculation | Standard atmosphere |
|---|---|---|
| 1 Torr | 1 Torr × 0.001315789 = 0.001315789 atm | 0.001315789 atm |
| 2 Torr | 2 Torr × 0.001315789 = 0.002631579 atm | 0.002631579 atm |
| 3 Torr | 3 Torr × 0.001315789 = 0.003947368 atm | 0.003947368 atm |
| 5 Torr | 5 Torr × 0.001315789 = 0.006578947 atm | 0.006578947 atm |
| 7 Torr | 7 Torr × 0.001315789 = 0.009210526 atm | 0.009210526 atm |
| 10 Torr | 10 Torr × 0.001315789 = 0.01315789 atm | 0.01315789 atm |
| 12 Torr | 12 Torr × 0.001315789 = 0.01578947 atm | 0.01578947 atm |
| 15 Torr | 15 Torr × 0.001315789 = 0.01973684 atm | 0.01973684 atm |
| 20 Torr | 20 Torr × 0.001315789 = 0.02631579 atm | 0.02631579 atm |
| 25 Torr | 25 Torr × 0.001315789 = 0.03289474 atm | 0.03289474 atm |
| 50 Torr | 50 Torr × 0.001315789 = 0.06578947 atm | 0.06578947 atm |
| 100 Torr | 100 Torr × 0.001315789 = 0.1315789 atm | 0.1315789 atm |
Common Torr to Standard atmosphere conversions
These are the torr-to-standard atmosphere values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 torr = 0.001315789 standard atmosphere
- 2 torr = 0.002631579 standard atmosphere
- 2.5 torr = 0.003289474 standard atmosphere
- 3 torr = 0.003947368 standard atmosphere
- 4 torr = 0.005263158 standard atmosphere
- 5 torr = 0.006578947 standard atmosphere
- 6 torr = 0.007894737 standard atmosphere
- 7 torr = 0.009210526 standard atmosphere
- 8 torr = 0.01052632 standard atmosphere
- 9 torr = 0.01184211 standard atmosphere
- 10 torr = 0.01315789 standard atmosphere
- 12 torr = 0.01578947 standard atmosphere
- 15 torr = 0.01973684 standard atmosphere
- 20 torr = 0.02631579 standard atmosphere
- 25 torr = 0.03289474 standard atmosphere
- 30 torr = 0.03947368 standard atmosphere
- 50 torr = 0.06578947 standard atmosphere
- 75 torr = 0.09868421 standard atmosphere
- 100 torr = 0.1315789 standard atmosphere
- 200 torr = 0.2631579 standard atmosphere
- 500 torr = 0.6578947 standard atmosphere
- 1000 torr = 1.315789 standard atmosphere
Torr to Standard atmosphere conversion chart (both directions)
The chart below converts torr to standard atmosphere and standard atmosphere to torr side by side, so it works whichever way you need. 1 torr = 0.001315789 standard atmosphere, and 1 standard atmosphere = 760 torr.
| Torr → Standard atmosphere | Standard atmosphere → Torr |
|---|---|
| 0.25 Torr = 0.0003289474 atm | 0.25 atm = 190 Torr |
| 0.5 Torr = 0.0006578947 atm | 0.5 atm = 380 Torr |
| 1 Torr = 0.001315789 atm | 1 atm = 760 Torr |
| 2 Torr = 0.002631579 atm | 2 atm = 1,520 Torr |
| 3 Torr = 0.003947368 atm | 3 atm = 2,280 Torr |
| 4 Torr = 0.005263158 atm | 4 atm = 3,040 Torr |
| 5 Torr = 0.006578947 atm | 5 atm = 3,800 Torr |
| 6 Torr = 0.007894737 atm | 6 atm = 4,560 Torr |
| 7 Torr = 0.009210526 atm | 7 atm = 5,320 Torr |
| 8 Torr = 0.01052632 atm | 8 atm = 6,080 Torr |
| 9 Torr = 0.01184211 atm | 9 atm = 6,840 Torr |
| 10 Torr = 0.01315789 atm | 10 atm = 7,600 Torr |
| 12 Torr = 0.01578947 atm | 12 atm = 9,120 Torr |
| 15 Torr = 0.01973684 atm | 15 atm = 11,400 Torr |
| 20 Torr = 0.02631579 atm | 20 atm = 15,200 Torr |
| 25 Torr = 0.03289474 atm | 25 atm = 19,000 Torr |
| 30 Torr = 0.03947368 atm | 30 atm = 22,800 Torr |
| 40 Torr = 0.05263158 atm | 40 atm = 30,400 Torr |
| 50 Torr = 0.06578947 atm | 50 atm = 38,000 Torr |
| 75 Torr = 0.09868421 atm | 75 atm = 57,000 Torr |
| 100 Torr = 0.1315789 atm | 100 atm = 76,000 Torr |
| 150 Torr = 0.1973684 atm | 150 atm = 114,000 Torr |
| 200 Torr = 0.2631579 atm | 200 atm = 152,000 Torr |
| 250 Torr = 0.3289474 atm | 250 atm = 190,000 Torr |
| 500 Torr = 0.6578947 atm | 500 atm = 380,000 Torr |
| 1000 Torr = 1.315789 atm | 1000 atm = 760,000 Torr |
Torr vs Standard atmosphere: which is bigger?
A standard atmosphere is the larger unit: one standard atmosphere equals 760 torrs. Put another way, you need 760 torrs to make a single standard atmosphere.
What is a Torr? History, origin and usage
The torr honours Evangelista Torricelli, who built the first mercury barometer in 1643 and correctly explained that the column was held up by the weight of the air outside. The unit was named in the 1940s, and was defined as exactly one 760th of a standard atmosphere so that it would be tied to a fixed number rather than to the behaviour of real mercury.
Torr is the working unit of vacuum technology — vacuum pumps, freeze dryers, electron microscopes, semiconductor process chambers and mass spectrometers are all specified in torr or its subdivisions.
Because it is defined as a 760th of an atmosphere, 760 torr is one atmosphere exactly, by construction. It is very nearly the same as a millimetre of mercury but not exactly: the two differ by about one part in seven million, a gap that matters only in precision metrology and is the reason careful documents never treat the two names as interchangeable.
What is a Standard atmosphere? History, origin and usage
The standard atmosphere was fixed by the 10th General Conference on Weights and Measures in 1954 at exactly 101,325 pascals. Before that, "one atmosphere" meant whatever a 760 mm mercury column happened to weigh, which depended on local gravity and on the temperature of the mercury — so the same experiment gave slightly different answers in different laboratories. Fixing it as a defined number ended that.
Atmospheres are used in chemistry, physics, diving and any field that talks about pressure as a multiple of ordinary air pressure — reaction conditions, gas laws, hyperbaric medicine and pressure-vessel ratings.
It is a defined constant, not a measurement, so it never changes with the weather or with where you are standing. Real sea-level pressure wanders a few per cent either side of it every week. The deepest point of the ocean sits at roughly 1,100 atmospheres.
Convert 1 Torr to other units
It can help to see a torr next to the other units it is commonly compared with. One torr (Torr) is equal to:
| 1 Torr equals | Unit |
|---|---|
| 133.3224 Pa | Pascal |
| 1.333224 hPa | Hectopascal |
| 0.1333224 kPa | Kilopascal |
| 0.0001333224 MPa | Megapascal |
| 1.333224 mbar | Millibar |
| 0.001333224 bar | Bar |
| 0.001315789 atm | Standard atmosphere |
| 0.9999999 mmHg | Millimetre of mercury |
| 0.03937007 inHg | Inch of mercury |
| 13.5951 mmH₂O | Millimetre of water |
| 0.5352401 inH₂O | Inch of water |
| 0.01933677 psi | Pound per square inch |
| 0.00135951 kgf/cm² | Kilogram-force per square centimetre |
Convert 1 Standard atmosphere to other units
One standard atmosphere (atm) is equal to:
| 1 Standard atmosphere equals | Unit |
|---|---|
| 101,325 Pa | Pascal |
| 1,013.25 hPa | Hectopascal |
| 101.325 kPa | Kilopascal |
| 0.101325 MPa | Megapascal |
| 1,013.25 mbar | Millibar |
| 1.01325 bar | Bar |
| 760 Torr | Torr |
| 759.9999 mmHg | Millimetre of mercury |
| 29.92126 inHg | Inch of mercury |
| 10,332.27 mmH₂O | Millimetre of water |
| 406.7825 inH₂O | Inch of water |
| 14.69595 psi | Pound per square inch |
| 1.033227 kgf/cm² | Kilogram-force per square centimetre |
Tips for converting Torr to Standard atmosphere
- To go from torr to standard atmosphere, multiply by 0.001315789; to go back, divide by 0.001315789 (or multiply by 760).
- For a quick mental estimate, remember that 1 torr ≈ 0.001315789 standard atmosphere, so 10 torr ≈ 0.01315789 standard atmosphere.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this Torr to Standard atmosphere converter
Type a number into the Torr field and the equivalent in Standard atmosphere appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Standard atmosphere field to convert the other way (standard atmosphere to torr). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 Torr = 0.001315789 atm), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for torr-to-standard atmosphere conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
- NIST — Definitions of the SI base units — the US National Institute of Standards and Technology reference for the SI base units, used here as an independent cross-check on the base-unit definition.
Pressure factors here come from fixed definitions, anchored to the pascal: a bar is exactly 100,000 Pa, one atmosphere is exactly 101,325 Pa, a torr is exactly a 760th of an atmosphere, and psi is built from the exact pound and the exact inch. Two of them — psi and the torr — work out to decimals that repeat forever, so where a number is shown rounded it is marked, not quietly trimmed.
Frequently asked questions
- How many standard atmosphere are in 1 torr?
- 1 torr = 0.001315789 standard atmosphere (atm). To convert any number of torr to standard atmosphere, multiply by 0.001315789.
- How do I convert torr to standard atmosphere?
- Multiply the number of torr by 0.001315789. For example, 10 torr = 10 × 0.001315789 = 0.01315789 standard atmosphere, and 25 torr = 0.03289474 standard atmosphere.
- How many torr are in 1 standard atmosphere?
- 1 standard atmosphere = 760 torr. So to convert standard atmosphere back to torr, multiply by 760.
- What is the formula to convert torr to standard atmosphere?
- standard atmosphere = torr × 0.001315789. The reverse formula is torr = standard atmosphere × 760.
- How much is 100 torr in standard atmosphere?
- 100 torr = 0.1315789 standard atmosphere. (And 1000 torr = 1.315789 standard atmosphere.)
- Which is bigger, a torr or a standard atmosphere?
- A standard atmosphere is larger: 1 standard atmosphere = 760 torr.
- Is this torr to standard atmosphere converter accurate?
- Yes — every value is computed from the exact 0.001315789 atm per Torr factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert standard atmosphere to torr too?
- Yes. The converter works both ways — enter a value in either field. 1 standard atmosphere = 760 torr.