Convert cubic inches to US gallons

1 in³=0.004329gal (US)

Use the converter below to change any cubic inches value into US gallons instantly — with formula, conversion table, and real-world examples.

You have

Equals

0.004329

Conversion formula

Forward

US gallons = cubic inches × 0.004329

Reverse

cubic inches = US gallons × 231

Example: 10 in³ × 0.004329 = 0.04329 gal (US).

About both units

From

Cubic Inch

in³

The cubic inch equals 16.387 cubic centimetres. Used in US automotive engineering for engine displacement (e.g., "350 cubic inch V8 = 5.7 L") and in firearms (bullet cartridges). Most of the rest of the world uses cc or litres.

Real-world: 350 cu in V8 = 5.7 L engine. 302 cu in Ford V8 = 4.9 L. Modern specs typically give litres.

Read full cubic inch reference →

US Gallon

gal (US)

The US gallon equals 3.785411784 litres exactly. It is the standard fuel and liquid volume unit in the United States. A typical American car holds 14–18 US gallons of fuel. US fuel economy is quoted in miles per US gallon (mpg).

Real-world: US car tank ≈ 15 gallons (57 L). 1 US gallon of milk is a common grocery size (3.79 L). US paint often sold by the gallon.

Read full us gallon reference →

Cubic Inch to US Gallon conversion table

Common cubic inches to US gallons values for quick reference.

Cubic Inch (in³)	US Gallon (gal (US))
1 in³	0.004329 gal (US)
2 in³	0.008658 gal (US)
5 in³	0.02165 gal (US)
10 in³	0.04329 gal (US)
20 in³	0.08658 gal (US)
50 in³	0.2165 gal (US)
100 in³	0.4329 gal (US)
200 in³	0.8658 gal (US)
500 in³	2.1645 gal (US)
1,000 in³	4.329 gal (US)

Tips & common mistakes

Quick tips

1 in³ = 16.387 cm³ exactly.
To convert cubic inches to litres, divide by 61.02.
US automotive ads today quote both cu in and L for classic cars.

Avoid these

Confusing in³ with in² or linear inches.
Using 16 instead of 16.387 on precision machining.
Assuming modern European engines are marked in cu in — they are always in L or cc.

Frequently asked questions

How many US gallons in a cubic inch?

One cubic inch equals 0.004329 US gallons.

How do I convert cubic inches to US gallons?

Multiply the cubic inch value by 0.004329 to get the equivalent in US gallons.

What is 100 cubic inches in US gallons?

100 cubic inches equals 0.4329 US gallons.

Is a cubic inch bigger than a us gallon?

No. 1 cubic inch equals 0.004329 US gallons, so one cubic inch is smaller.

How to convert cubic inches to US gallons without a calculator?

Multiply by 0 for a quick estimate; use a calculator for precise results.

Related volume conversions

📊 See full comparison matrix →

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