Attopascal is 1e-18 pascal units.
Attopascals to Torrs Converter — aPa to Torr
Convert Attopascal (aPa) to Torr (Torr) using the exact conversion factor (1 attopascal = 7.500617e-21 torr). See the formula, worked examples, and conversion table.
Attopascals to Torrs converter
Converter
Pressure Converter
Convert pascals, bars, PSI, atmospheres, mercury columns, water columns, and engineering pressure units.
Context values
Some unit families need one extra value for a physically accurate result.
A torr is 1/760 standard atmosphere.
Result = input x 1e-18 / 133.3223684.
Pressure uses the pascal as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Attopascals to Torrs
Attopascal and Torr both show up on pressure gauges — psi is standard on US tire and tool specifications, while bar is the everyday pressure unit across most of the rest of the world. Specifically: Attopascal is 1e-18 pascal units, and a torr is 1/760 standard atmosphere.
Formula
torrs = attopascals × 7.500617e-21
This factor comes from each unit's defined relationship to the category's base unit: 1 attopascal equals 1e-18 base units, and 1 torr equals 133.322368421 base units, so dividing one by the other gives the direct attopascal-to-torr factor of 7.500617e-21.
Simple example
1 aPa × 7.500617e-21 = 7.500617e-21 Torr
1 attopascal = 7.500617e-21 torrs.
Real-world example
35 aPa × 7.500617e-21 = 2.625216e-19 Torr
35 attopascals = 2.625216e-19 torrs.
Conversion table
| Attopascal (aPa) | Torr (Torr) |
|---|---|
| 1 aPa | 7.500617e-21 Torr |
| 5 aPa | 3.750308e-20 Torr |
| 10 aPa | 7.500617e-20 Torr |
| 25 aPa | 1.875154e-19 Torr |
| 50 aPa | 3.750308e-19 Torr |
| 100 aPa | 7.500617e-19 Torr |
Reverse conversion: Torr to Attopascal
7.500617e-21 Torr × 1.333224e+20 = 1.000000023 aPa
7.500617e-21 torrs = 1.000000023 attopascals.
attopascals = torrs × 1.333224e+20
For a page dedicated to this direction, see Torr to Attopascal.
Understanding the Attopascal (aPa)
Attopascal is 1e-18 pascal units.
Understanding the Torr (Torr)
A torr is 1/760 standard atmosphere.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many torrs are in 1 attopascal?
1 attopascal equals 7.500617e-21 torrs, using the exact defined conversion factor rather than an estimate.
How do I convert attopascal to torr?
Multiply the attopascal value by 7.500617e-21. The converter above does this instantly to whatever precision you set.
How do I convert torr back to attopascal?
Use the reverse factor: 1 torr equals 1.333224e+20 attopascals. You can also use the swap control in the converter above to flip the direction instantly.
What is a attopascal?
Attopascal (aPa) is a unit of pressure.
What is a torr?
Torr (Torr) is a unit of pressure.
Is the attopascal to torr conversion exact?
Yes. Both attopascal and torr are defined by fixed standards rather than physical artifacts, so the factor of 7.500617e-21 used above is exact to as many digits as you choose to display.