---
title: "Inches of mercury to Standard atmospheres converter"
description: "1 inch of mercury = 0.033421 standard atmospheres. Conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/inches-of-mercury-to-atmospheres/
site: "At One Place"
---

# Inches of mercury to standard atmospheres

**1 inch of mercury in standard atmospheres: 1 inHg = 0.033421 atm**

atm = inHg × 0.03342106094

To convert inches of mercury to standard atmospheres, multiply by 0.03342106094. The table below gives the values people look up most often, and the converter works for any number.

## Inches of mercury to standard atmospheres table

*Common inch of mercury values converted to standard atmospheres.*

| Inches of mercury | Standard atmospheres |
| --- | --- |
| 1 inHg | 0.033421 |
| 2 inHg | 0.066842 |
| 3 inHg | 0.10026 |
| 4 inHg | 0.13368 |
| 5 inHg | 0.16711 |
| 10 inHg | 0.33421 |
| 15 inHg | 0.50132 |
| 20 inHg | 0.66842 |
| 25 inHg | 0.83553 |
| 30 inHg | 1.002632 |
| 40 inHg | 1.336842 |
| 50 inHg | 1.671053 |
| 75 inHg | 2.50658 |
| 100 inHg | 3.342106 |
| 250 inHg | 8.355265 |
| 500 inHg | 16.71053 |
| 1,000 inHg | 33.42106 |

## How the conversion works

The relationship is atm = inHg × 0.03342106094. Both units measure pressure, so the conversion is a fixed factor that never changes.

## Common questions

### How many standard atmospheres are in one inch of mercury?

One inch of mercury equals 0.033421 standard atmospheres. atm = inHg × 0.03342106094.

### How do you convert inches of mercury to standard atmospheres?

Use atm = inHg × 0.03342106094. So 10 inHg is 0.33421 atm.

### How many inches of mercury are in one standard atmosphere?

One standard atmosphere equals 29.92125 inches of mercury, which is the reverse of the conversion above.

## Related pages

- [Standard atmospheres to Inches of mercury](https://atoneplace.net/convert/atmospheres-to-inches-of-mercury/)
- [Inches of mercury to Pascals](https://atoneplace.net/convert/inches-of-mercury-to-pascals/)
- [Inches of mercury to Kilopascals](https://atoneplace.net/convert/inches-of-mercury-to-kilopascals/)
- [Inches of mercury to Bars](https://atoneplace.net/convert/inches-of-mercury-to-bar/)
- [Inches of mercury to Pounds per square inch](https://atoneplace.net/convert/inches-of-mercury-to-psi/)
- [Inches of mercury to Torrs](https://atoneplace.net/convert/inches-of-mercury-to-torr/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)