Gallons to Cubic Inches Calculator

Convert US gallons (gal) to cubic inches (in³) accurately. Uses the exact legal US definition: 1 gallon = 231 cubic inches.

Volume ConverterLive
Precision:
gal
Formulan gal × 231 = ? in³

Quick Values

How to Convert US Gallons to Cubic Inches

in³ = gal × 231 (1 US gallon = 231 in³ exactly)

1 US gallon = exactly 231 cubic inches — the US legal definition since 1836.

A 5-gallon bucket = 1,155 cubic inches of volume.

Note: 1 Imperial (UK) gallon = 277.42 in³, not 231.

To reverse: divide cubic inches by 231.

US GallonsCubic Inches Reference Table

US Gallons (gal)Cubic Inches (in³)
1231
2462
51,155
102,310
255,775
5011,550
10023,100
25057,750
500115,500
1,000231,000

Click any row to load into the calculator.

📦Unit Reference

US Gallons

1 gal = 231 in³

Cubic Inches

1 in³ = 0.0043 gal

✅ Common Use Cases

  • Engine displacement (automotive)
  • Aquarium & tank sizing
  • Shipping & packaging volume
  • Fuel & fluid calculations
  • HVAC duct sizing
  • 3D printing volume estimation

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