Calculator Form
Example Data Table
| mmHg | atm | kPa |
|---|---|---|
| 190 | 0.2500 | 25.331 |
| 380 | 0.5000 | 50.663 |
| 760 | 1.0000 | 101.325 |
| 1,140 | 1.5000 | 151.988 |
| 1,520 | 2.0000 | 202.650 |
These sample rows help verify expected pressure relationships before entering your own value.
Formula Used
This converter treats “mm” as mmHg, which is standard for pressure conversion into atmospheres.
- atm = mmHg ÷ reference mmHg per atm
- mmHg = atm × reference mmHg per atm
- kPa = atm × 101.325
- bar = atm × 1.01325
- psi = atm × 14.6959
The default reference is 760 mmHg for 1 atmosphere, but you can edit it for custom calibration or teaching examples.
How to Use This Calculator
- Select whether you want to convert from mmHg to atm or from atm to mmHg.
- Enter the pressure value you want to convert.
- Keep the default reference of 760 unless your process requires a different standard.
- Choose decimal places, graph sample points, and graph range.
- Click Convert Now to show the result above the form.
- Review the secondary pressure units, graph, and generated table.
- Use the CSV or PDF buttons to export your result set.
Frequently Asked Questions
1. What does mm mean in this converter?
In this calculator, mm means millimeters of mercury, written as mmHg. That is the standard pressure unit commonly converted into atmospheres in laboratory, medical, and engineering contexts.
2. How many mmHg are in 1 atm?
One atmosphere equals 760 mmHg under the standard reference used in most textbooks and instruments. The calculator uses that value by default, but you can change it manually.
3. Why does the tool also show kPa, bar, psi, and torr?
Pressure work often crosses different standards. Showing extra units lets you compare scientific, industrial, and instrument-based readings without opening another converter or recalculating the same input multiple times.
4. Can I convert atm back into mmHg?
Yes. Choose the reverse conversion direction in the form. The calculator will multiply the entered atmospheres by the reference mmHg-per-atm value and show the converted pressure immediately.
5. What is the purpose of the reference field?
The reference field controls the conversion baseline. Most users should keep 760, but instructors, calibration tasks, or custom models may require a different pressure equivalence for comparison.
6. Why is the graph useful for a simple converter?
The graph shows how converted values move around your input across a chosen range. It helps with trend checking, sensitivity review, and presenting pressure relationships visually in reports.
7. When should I use scientific notation?
Use scientific notation when your pressure values are extremely small, extremely large, or when you want compact formatting for technical documents, laboratory notes, and engineering calculations.
8. Does the calculator work on phones and tablets?
Yes. The layout is responsive. Input fields appear in three columns on large screens, two on medium screens, and one on mobile devices for easier data entry.