---
title: "21 st to t = 0.13336 t"
description: "21 stone is 0.13336 tonnes. The arithmetic, a table of nearby values, and a converter for any other number."
url: https://atoneplace.net/convert/21-stone-to-tonnes/
site: "At One Place"
---

# 21 st to t

**21 stone in tonnes: 21 st = 0.13336 t**

t = st × 0.00635029318

21 stone is 0.13336 tonnes. To get there, multiply by 0.00635029318.

## Values either side

*Stone near 21, converted to tonnes.*

| Stone | Tonnes |
| --- | --- |
| 17 st | 0.10795 |
| 18 st | 0.11431 |
| 19 st | 0.12066 |
| 20 st | 0.12701 |
| 21 st ← | 0.13336 |
| 22 st | 0.13971 |
| 23 st | 0.14606 |
| 24 st | 0.15241 |
| 25 st | 0.15876 |

## How the conversion works

The relationship is t = st × 0.00635029318. Both units measure mass, so the conversion is a fixed factor that never changes. The figure is exact rather than approximate: since the international yard and pound agreement of 1959, an inch is defined as exactly 25.4 millimetres and a pound as exactly 0.45359237 kilograms, and every other imperial and US customary unit here is derived from those two.

> Tonne: Also called a metric ton.

## Common questions

### What is 21 st in tonnes?

21 st is 0.13336 t.

### How do you convert stone to tonnes?

Multiply by 0.00635029318.

## Related pages

- [Stone to tonnes](https://atoneplace.net/convert/stone-to-tonnes/)
- [21 t to st](https://atoneplace.net/convert/21-tonnes-to-stone/)
- [17 st to t](https://atoneplace.net/convert/17-stone-to-tonnes/)
- [18 st to t](https://atoneplace.net/convert/18-stone-to-tonnes/)
- [19 st to t](https://atoneplace.net/convert/19-stone-to-tonnes/)
- [20 st to t](https://atoneplace.net/convert/20-stone-to-tonnes/)
- [22 st to t](https://atoneplace.net/convert/22-stone-to-tonnes/)
- [23 st to t](https://atoneplace.net/convert/23-stone-to-tonnes/)
- [24 st to t](https://atoneplace.net/convert/24-stone-to-tonnes/)
- [25 st to t](https://atoneplace.net/convert/25-stone-to-tonnes/)

## 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/)