---
title: "21 qt to gal = 5.25 gal"
description: "21 US quarts is 5.25 US gallons. The arithmetic, a table of nearby values, and a converter for any other number."
url: https://atoneplace.net/convert/21-quarts-to-gallons/
site: "At One Place"
---

# 21 qt to gal

**21 US quarts in US gallons: 21 qt = 5.25 gal**

gal = qt × 1/4

21 US quarts is 5.25 US gallons. To get there, multiply by 0.25.

## Values either side

*US quarts near 21, converted to US gallons.*

| US quarts | US gallons |
| --- | --- |
| 17 qt | 4.25 |
| 18 qt | 4.5 |
| 19 qt | 4.75 |
| 20 qt | 5 |
| 21 qt ← | 5.25 |
| 22 qt | 5.5 |
| 23 qt | 5.75 |
| 24 qt | 6 |
| 25 qt | 6.25 |

## How the conversion works

The relationship is gal = qt × 1/4. Both units measure volume, 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.

> US gallon: US liquid gallon. The imperial gallon is about 20% larger.

## Common questions

### What is 21 qt in US gallons?

21 qt is 5.25 gal.

### How do you convert US quarts to US gallons?

Multiply by 0.25.

## Related pages

- [US quarts to US gallons](https://atoneplace.net/convert/quarts-to-gallons/)
- [21 gal to qt](https://atoneplace.net/convert/21-gallons-to-quarts/)
- [17 qt to gal](https://atoneplace.net/convert/17-quarts-to-gallons/)
- [18 qt to gal](https://atoneplace.net/convert/18-quarts-to-gallons/)
- [19 qt to gal](https://atoneplace.net/convert/19-quarts-to-gallons/)
- [20 qt to gal](https://atoneplace.net/convert/20-quarts-to-gallons/)
- [22 qt to gal](https://atoneplace.net/convert/22-quarts-to-gallons/)
- [23 qt to gal](https://atoneplace.net/convert/23-quarts-to-gallons/)
- [24 qt to gal](https://atoneplace.net/convert/24-quarts-to-gallons/)
- [25 qt to gal](https://atoneplace.net/convert/25-quarts-to-gallons/)

## 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/)