---
title: "Grains to Tonnes — gr to t converter"
description: "1 grain = 6.48 × 10^-8 tonnes. Convert grains to tonnes with a full conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/grains-to-tonnes/
site: "At One Place"
---

# Grains to tonnes

**1 grain in tonnes: 1 gr = 6.48 × 10^-8 t**

t = gr × 6.479891 × 10^-8

To convert grains to tonnes, multiply by 6.479891 × 10^-8. The table below gives the values people look up most often, and the converter works for any number.

## Grains to tonnes table

*Common grain values converted to tonnes.*

| Grains | Tonnes |
| --- | --- |
| 1 gr | 6.48 × 10^-8 |
| 2 gr | 1.296 × 10^-7 |
| 3 gr | 1.944 × 10^-7 |
| 4 gr | 2.592 × 10^-7 |
| 5 gr | 3.24 × 10^-7 |
| 10 gr | 6.48 × 10^-7 |
| 15 gr | 9.72 × 10^-7 |
| 20 gr | 0.000001296 |
| 25 gr | 0.00000162 |
| 30 gr | 0.000001944 |
| 40 gr | 0.000002592 |
| 50 gr | 0.00000324 |
| 75 gr | 0.00000486 |
| 100 gr | 0.00000648 |
| 250 gr | 0.0000162 |
| 500 gr | 0.0000324 |
| 1,000 gr | 0.0000648 |

## How the conversion works

The relationship is t = gr × 6.479891 × 10^-8. Both units measure mass, so the conversion is a fixed factor that never changes.

> Tonne: Also called a metric ton.

## Common questions

### How many tonnes are in one grain?

One grain equals 6.48 × 10^-8 tonnes. t = gr × 6.479891 × 10^-8.

### How do you convert grains to tonnes?

Use t = gr × 6.479891 × 10^-8. So 10 gr is 6.48 × 10^-7 t.

### How many grains are in one tonne?

One tonne equals 15,432,358 grains, which is the reverse of the conversion above.

### Is there more than one kind of tonne?

Also called a metric ton.

## Related pages

- [Tonnes to Grains](https://atoneplace.net/convert/tonnes-to-grains/)
- [Grains to Kilograms](https://atoneplace.net/convert/grains-to-kg/)
- [Grains to Grams](https://atoneplace.net/convert/grains-to-grams/)
- [Grains to Milligrams](https://atoneplace.net/convert/grains-to-mg/)
- [Grains to Pounds](https://atoneplace.net/convert/grains-to-lbs/)
- [Grains to Ounces](https://atoneplace.net/convert/grains-to-oz/)
- [Grains to Stone](https://atoneplace.net/convert/grains-to-stone/)

## 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/)