# Gallons to Quarts Converter

URL: https://speedycalculator.com/calculators/conversion/gallons-to-quarts/
Last updated: 2026-10-25

> Convert US gallons (US gal) to US quarts (US qt): 1 US gallon = 4 US qt, so multiply by 4 or divide by 0.25. Both fields are editable, so you can also type in US quarts and get US gallons back.

## Inputs

- US gallons (US gal)

## Results

- US quarts

## Formula

```
1 US gal = 4 US qt
1 US qt = 0.25 US gal
US qt = US gal × 4
```

## Explanation

A gallon is four quarts; the name quart comes from “quarter gallon”. Engine oil and paint are often sold in both sizes.

### How to use the Gallons to Quarts Converter

- Type the number of US gallons into the **US gallons** field. Decimals such as 0.5 are fine.
- Read the answer in **US quarts** – it updates as you type, with no button to press.
- To convert the other way, type into **US quarts** and the US gallons are recalculated.
- Press **Copy results** to copy both values with the page title, or **Copy link** to share this exact conversion.

This page converts only US gal ⇄ US qt. Need a different unit? Use the general volume converter, where you can choose any “from” and “to” unit.

### How it works

Both units measure volume, so they are always in the same ratio: one US gallon equals 4 US quarts. The calculator multiplies the number of US gallons you type by 4 to give US quarts, and when you type into the US quarts field it divides by the same factor to give US gallons. Because the ratio never changes, doubling the US gallons always doubles the US quarts. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation).

### How to convert US gallons to US quarts

- Write down the value in US gallons, for example **1 US gal**.
- Multiply by the conversion factor 4 (because 1 US gallon = 4 US qt).
- 1 × 4 = **4 US qt**.
- To go back from US quarts to US gallons, divide by 4 – or multiply by 0.25.

### US gal to US qt conversion table

US gallonsUS quartsUS quartsUS gallons0.25 US gal1 US qt1 US qt0.25 US gal0.5 US gal2 US qt2 US qt0.5 US gal1 US gal4 US qt5 US qt1.25 US gal1.5 US gal6 US qt10 US qt2.5 US gal2 US gal8 US qt20 US qt5 US gal5 US gal20 US qt50 US qt12.5 US gal10 US gal40 US qt100 US qt25 US gal1,000 US qt250 US gal

### What is a US gallon?

The U.S. liquid gallon is exactly 231 cubic inches, about 3.785 litres. It is used for fuel, milk, water and paint in the United States.

### What is a US quart?

A U.S. quart is a quarter of a gallon, about 946 mL. Engine oil, ice cream and soups are often sold by the quart.

### Common mistakes to avoid

Mixing u.s. and uk gallons, pints and fluid ounces, assuming a cup is always 250 ml, and treating volume and weight as interchangeable for anything except water.

## Worked example

Inputs — US gallons: 1 US gal.

Results — **US quarts = 4 US qt**.

## FAQ

**How many quarts in a gallon?**
4.

**How many quarts in 2.5 gallons?**
10.

**How many US quarts are in one US gallon?**
1 US gal = 4 US qt.

**How many US gallons are in one US quart?**
1 US qt = 0.25 US gal.

**How do I convert US gallons to US quarts?**
Multiply the number of US gallons by 4. For example, 1 US gal × 4 = 4 US qt.

**How do I convert US quarts back to US gallons?**
Divide by 4 (or multiply by 0.25), or simply type the value into the US quarts field above.

**What is 10 US gal in US quarts?**
10 US gal = 40 US qt.

**What is 5 US gal in US quarts?**
5 US gal = 20 US qt.

**Is this conversion exact?**
Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit.

**Can I convert to other units on this page?**
This page converts only between US gallons and US quarts. To pick any volume unit, use the general volume converter linked under Related calculators.

**What formula does the Gallons to Quarts Converter use?**
1 US gal = 4 US qt.


## Sources

- [NIST Special Publication 811 – Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811)
- [NIST Handbook 44 Appendix C – General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)