# PSI to Bar Converter

> PSI to bar converter: convert psi to bar and bar to psi using the exact definition 1 bar = 14.503773773 psi, with a reference table. Free, instant, runs in your browser.

- **Canonical URL:** https://boringtoolskit.com/psi-to-bar/
- **Category:** Converters
- **Evidence level:** authored-methodology
- **Reviewed:** 2026-09-20
- **Last verified:** 2026-09-20
- **Privacy:** Inputs and results stay in this browser unless the page clearly labels an external request.

## How it works

value × source factor ÷ target factor via the pascal base unit

## Worked example

1 psi = 6.895 kilopascal · 1 bar = 1e+05 pascal · 1 atmosphere = 101.3 kilopascal

## Assumptions

- Inputs are treated as exact decimal values.
- Standard (not historical or survey) unit definitions are used.
- Rounding is display-only; the calculator keeps full precision internally.

## Common questions

### Why convert through pascal instead of directly?

Routing every unit through a single base (pascal) means each unit needs only one exact factor against the standard, and any pair combines cleanly. Direct pair factors drift apart over time in hand-maintained tables; a base-unit graph cannot.

### Where do these exact factors come from?

From published standards (NIST: SP 811 pressure conversions). Units like the inch are defined exactly (1 in = 2.54 cm since 1959), so conversions between standard units are exact, not approximate.

### How many decimal places should I trust?

The math is exact to the precision shown. The practical limit is your input: a tape measure is only good to ~1 mm and a kitchen scale to ~1 g, so 3–4 significant figures already exceeds the measurement's own accuracy.

## Sources

- [SP 811 pressure conversions](https://www.nist.gov/pml/weights-and-measures)

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