Convert Imperial Gallon to Metric Cup
Convert imperial gallons to metric cups instantly. 1 imperial gallon = 18.18436 metric cup — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Metric Cup to Imperial Gallon converter for the reverse conversion.
Units explained
Imperial Gallon
The imperial gallon is defined as exactly 4.54609 liters.
Set by the British Weights and Measures Act of 1824 as the volume of 10 lb of water.
Used for fuel and beverages in the UK and Commonwealth.
UK, 1824.
Metric Cup
A metric cup is exactly 250 milliliters.
Adopted with metrication in Australia, New Zealand and other countries.
Standard cooking cup in metric-recipe countries.
Metrication, 20th c.
Imperial Gallon to Metric Cup conversion formula
The relationship between imperial gallons and metric cups:
To convert imperial gallons to metric cups, multiply the value in imperial gallons by 18.18436. To reverse, multiply metric cups by 0.0549923121.
How to use this converter
Type a value into the calculator. The result in metric cups updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Metric Cup to Imperial Gallon converter for the reverse direction.
Step-by-step: convert imperial gallons to metric cups
- Write down the value in imperial gallons (gal).
- Multiply that value by the factor 18.18436.
- The product is the equivalent value in metric cups (cup).
- To reverse, multiply the metric cup value by 0.0549923121.
Worked examples
Example 1 — Convert 1 gal to cup:
1 × 18.18436 = 18.18436 cup
Example 2 — Convert 100 gal to cup:
100 × 18.18436 = 1818.436 cup
Real-world example — Adjacent metric sub-units
One imperial gallon equals 1,000 metric cups. Engineers move between these scales constantly: PCB feature sizes in the larger unit, wire-bond diameters in the smaller.
1 gal × 18.18436 = 18.18436 cup
Real-world example — Adjacent small-scale precision
One imperial gallon equals 1,000 metric cups — the standard sub-millimeter precision conversion that materials engineers use whenever they switch between bulk material thickness specs (larger unit) and surface-finish characteristics (smaller unit).
1 gal × 18.18436 = 18.18436 cup
Imperial Gallon to Metric Cup conversion table
Standard reference values for converting imperial gallons to metric cups:
| Imperial Gallon [gal] | Metric Cup [cup] |
|---|---|
| 0.01 | 0.1818436 |
| 0.1 | 1.818436 |
| 1 | 18.18436 |
| 2 | 36.36872 |
| 3 | 54.55308 |
| 4 | 72.73744 |
| 5 | 90.9218 |
| 10 | 181.8436 |
| 20 | 363.6872 |
| 30 | 545.5308 |
| 40 | 727.3744 |
| 50 | 909.218 |
| 100 | 1818.436 |
| 500 | 9092.18 |
| 1000 | 18184.36 |
Frequently asked questions
How many metric cups is 1 imperial gallon?
How do I convert imperial gallons to metric cups?
How do I convert metric cups back to imperial gallons?
How many metric cups is 100 imperial gallons?
Popular volume unit conversions
Convert Imperial Gallon to other volume units
Show all Imperial Gallon conversions
Metric / SI (15 units)
US Customary (Liquid) (15 units)
US Customary (Dry) (5 units)
Imperial (UK) (13 units)
Cubic (length-derived) (4 units)
Cooking / Culinary (5 units)
Sources & references
Conversion factor (1 gal = 18.18436 cup) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.