Cubic Inches to UK Gallons (in³ to imp gal) Converter
1 cubic inch (in³) = 0.00360465 UK gallons (imp gal). To convert cubic inches to UK gallons, multiply by 0.00360465: 25 in³ × 0.00360465 = 0.0901163 imp gal.
Quick facts
- 1 in³ = 0.00360465 imp gal
- 1 imp gal = 277.419 in³
- Formula: imp gal = in³ × 0.00360465
- Quick estimate: multiply by about 0.0036
How to convert cubic inches to UK gallons
- Write down the number of cubic inches you have.
- Multiply it by 0.00360465 (the number of UK gallons in one cubic inch).
- Round the answer to a sensible number of decimal places.
Worked example: 25 in³ × 0.00360465 = 0.0901163 imp gal.
To convert UK gallons back to cubic inches, multiply by 277.419, or divide by 0.00360465.
Source: NIST Handbook 44, Appendix C, and NIST SP 811 (US customary volume units).
Cubic Inches to UK Gallons conversion table
| Cubic Inches [in³] | UK Gallons [imp gal] |
|---|---|
| 0.01 in³ | 0.0000360465 imp gal |
| 0.1 in³ | 0.000360465 imp gal |
| 1 in³ | 0.0036046501 imp gal |
| 2 in³ | 0.0072093003 imp gal |
| 3 in³ | 0.0108139504 imp gal |
| 5 in³ | 0.0180232507 imp gal |
| 10 in³ | 0.0360465015 imp gal |
| 20 in³ | 0.072093003 imp gal |
| 50 in³ | 0.1802325075 imp gal |
| 100 in³ | 0.360465015 imp gal |
| 1000 in³ | 3.6046501499 imp gal |
in³ to imp gal chart from 1 to 100
- 1 in³ 0.00360465 imp gal
- 2 in³ 0.0072093 imp gal
- 3 in³ 0.010814 imp gal
- 4 in³ 0.0144186 imp gal
- 5 in³ 0.0180233 imp gal
- 6 in³ 0.0216279 imp gal
- 7 in³ 0.0252326 imp gal
- 8 in³ 0.0288372 imp gal
- 9 in³ 0.0324419 imp gal
- 10 in³ 0.0360465 imp gal
- 11 in³ 0.0396512 imp gal
- 12 in³ 0.0432558 imp gal
- 13 in³ 0.0468605 imp gal
- 14 in³ 0.0504651 imp gal
- 15 in³ 0.0540698 imp gal
- 16 in³ 0.0576744 imp gal
- 17 in³ 0.0612791 imp gal
- 18 in³ 0.0648837 imp gal
- 19 in³ 0.0684884 imp gal
- 20 in³ 0.072093 imp gal
- 25 in³ 0.0901163 imp gal
- 30 in³ 0.10814 imp gal
- 35 in³ 0.126163 imp gal
- 40 in³ 0.144186 imp gal
- 45 in³ 0.162209 imp gal
- 50 in³ 0.180233 imp gal
- 55 in³ 0.198256 imp gal
- 60 in³ 0.216279 imp gal
- 65 in³ 0.234302 imp gal
- 70 in³ 0.252326 imp gal
- 75 in³ 0.270349 imp gal
- 80 in³ 0.288372 imp gal
- 85 in³ 0.306395 imp gal
- 90 in³ 0.324419 imp gal
- 95 in³ 0.342442 imp gal
- 100 in³ 0.360465 imp gal
UK Gallons to Cubic Inches conversion table
| UK Gallons [imp gal] | Cubic Inches [in³] |
|---|---|
| 0.01 imp gal | 2.7741943279 in³ |
| 0.1 imp gal | 27.7419432792 in³ |
| 1 imp gal | 277.4194327916 in³ |
| 2 imp gal | 554.8388655832 in³ |
| 3 imp gal | 832.2582983749 in³ |
| 5 imp gal | 1387.0971639581 in³ |
| 10 imp gal | 2774.1943279162 in³ |
| 20 imp gal | 5548.3886558324 in³ |
| 50 imp gal | 13870.9716395811 in³ |
| 100 imp gal | 27741.9432791622 in³ |
| 1000 imp gal | 277419.4327916215 in³ |
Cubic Inches vs UK Gallons
| Cubic Inch | UK Gallon | |
|---|---|---|
| Symbol | in³ | imp gal |
| Equals | 1 in³ = 0.00360465 imp gal | 1 imp gal = 277.419 in³ |
What is a cubic inch?
The volume of a cube with 1-inch sides. Used in the US for small mechanical parts and engine displacement.
What is a UK gallon?
The imperial gallon, defined as exactly 4.54609 litres (UK Weights and Measures Act 1985); about 20% larger than the US gallon. Used in the UK and Canada for fuel economy (miles per gallon), garden and aquarium volumes, and older fuel prices.
Where You Will Meet Cubic Inches and UK Gallons
Cubic inches are used mainly in the United States, while UK gallons are used mainly in the UK (pub pints, fuel economy in mpg) and older Canadian recipes. This conversion bridges the US customary and metric systems, so it comes up whenever a figure crosses the US border with Canada or the Atlantic with the UK: product specifications, travel, recipes, school work and trade.
How big is 1 in³ compared with 1 imp gal?
1 in³ is only 0.00360465 of 1 imp gal: you need 277.419 cubic inches to make 1 imp gal, so the number gets smaller when you convert.
Cubic Inches to UK Gallons without a calculator
- In your head: multiply by 0.004 (about 11% off). 231 in³ × 0.004 ≈ 0.924 imp gal.
- Closer estimate: multiply by 0.0036 (within 0.13%).
- Or divide: divide by 280 (within 0.93%), which is often easier than multiplying by a small decimal.
Real-world in³ to imp gal examples
| Example | Cubic Inches | UK Gallons |
|---|---|---|
| A 350 cubic-inch V8 engine | 350 in³ | 1.26163 imp gal |
| One US gallon | 231 in³ | 0.832674 imp gal |
| One imperial gallon | 277.419 in³ | 1 imp gal |
| A small aquarium | 2774.19 in³ | 10 imp gal |
| A garden water butt | 12483.9 in³ | 45 imp gal |
How exact is the in³ to imp gal factor?
The factor is exact by definition, so any error comes only from rounding. Keep at least 4 significant figures for school work, and the full factor for anything legal or commercial.
Mistakes to avoid
- This page uses the imperial (UK) measure. A US measure with the same name is smaller, so make sure your source is British or older Canadian.
- Volume factors are the cube of length factors, so a small rounding error in the length becomes three times larger in the volume.
Background on cubic inches and UK gallons
The imperial gallon was introduced in 1824 and is defined as exactly 4.54609 litres.
Related conversions
Related conversions you may need next: cubic inches to us gallons, uk gallons to liters, uk gallons to us gallons and liters to uk gallons. The full volume converter lists every unit.
On pakmath.com, the percentage calculator is a useful next step; for related everyday maths, try the gas mileage calculator on Adzita.
Frequently asked questions
How many UK gallons are in a cubic inch?
There are 0.00360465 UK gallons in 1 cubic inch (1 in³ = 0.0036046501 imp gal).
How many cubic inches are in a UK gallon?
There are 277.419 cubic inches in 1 UK gallon (1 imp gal = 277.4194327916 in³).
How do I convert cubic inches to UK gallons?
Multiply the number of cubic inches by 0.00360465. For example, 10 in³ × 0.00360465 = 0.0360465 imp gal. To convert back, multiply by 277.419.
What is 10 in³ in UK gallons?
10 in³ = 0.0360465 imp gal.
What is 100 in³ in UK gallons?
100 in³ = 0.360465 imp gal.
How accurate is this cubic inch to UK gallon converter?
Yes. The factor comes from the official definitions of both units (NIST Handbook 44, Appendix C, and NIST SP 811 (US customary volume units)). Results are shown to up to 10 decimal places; round them to suit your purpose.
What is an easy way to convert cubic inches to UK gallons?
In your head: multiply by 0.004 (about 11% off). 231 in³ × 0.004 ≈ 0.924 imp gal.
How many UK gallons is 350 in³ (a 350 cubic-inch V8 engine)?
350 in³ = 1.26163 imp gal.
How many cubic inches is a small aquarium (10 imp gal)?
10 imp gal = 2774.19 in³.
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