How many cubic meters are in a gallon?

One imperial gallon is exactly 0.00454609 m³ and one US liquid gallon exactly 0.003785411784 m³, using their definitions of 4.54609 L and 231 international cubic inches respectively. The cross-system ratio is not a terminating decimal: 1 imperial gallon displays as 1.2009499255 US gal and 1 US gal as 0.832674184629 imperial gal. The exact definitions are retained, while outputs round to twelve significant digits.

What is the formula for gallons to cubic meters?

m³ = imperial gallons × 0.00454609, or m³ = US gallons × 0.003785411784. Both come from the litre, which is this converter's base unit for volume: a cubic metre is exactly 1,000 litres, so a gallon in litres divided by 1,000 is the same gallon in cubic metres. Reversed, one cubic metre is 219.969248299 imperial gallons or 264.172052358 US gallons.

Worked example: what is 100 gallons in cubic meters?

100 imperial gallons is 0.454609 m³ and 100 US gallons is 0.3785411784 m³. The same factors give: 5 imperial gallons is 0.02273045 m³, 50 is 0.2273045 m³, 500 is 2.273045 m³ and 1,000 is 4.54609 m³. In US gallons, 1,000 is 3.785411784 m³.

Which gallon is my figure in?

Use the source’s explicit definition or documented unit convention. A bare gallon label does not establish whether it means US liquid, imperial or a separate dry measure. This page opens on the imperial gallon of exactly 4.54609 L and offers the US liquid gallon of exactly 3.785411784 L in the same From menu. Changing From reinterprets the typed scalar quantity. The US gallon readout for 1 imperial gallon displays as 1.2009499255 US gal; it does not identify the convention of an external label.

How do I convert cubic meters back to gallons?

Press the swap button between the two boxes and the page runs cubic metres into imperial gallons: 1 m³ is 219.969248299 gallons, 0.5 m³ is 109.98462415 gallons and 10 m³ is 2,199.69248299 gallons. The same cubic metre is 264.172052358 US gallons once you pick Gallon (US) in the To menu. Swap keeps the number you typed rather than the answer, so it converts that figure in the new direction.

Is a cubic metre the same as 1,000 litres?

Yes, exactly, and the converter is built that way: the litre is the base unit for volume here and the cubic metre carries a factor of exactly 1,000. So 1 m³ is 1,000 L, 1 L is 0.001 m³, and an imperial gallon of 4.54609 L becomes 0.00454609 m³ with the decimal point moved three places. A US gallon of 3.785411784 L becomes 0.003785411784 m³ the same way.

Why did a small number come back as 4.54609e-7?

Because anything below 0.000001 is printed in exponential notation rather than as a row of leading zeros. 0.0001 imperial gallons is 4.54609e-7 m³, while 0.1 gallons stays decimal at 0.000454609 m³. At that size the friendlier rows are already in the list underneath: 0.1 imperial gallons is 0.454609 L and 454.609 mL.

Does it know the US dry gallon?

No. The volume menu holds one US gallon, the liquid one of 231 cubic inches, next to the imperial gallon, US teaspoons, tablespoons, fluid ounces, cups, pints and quarts, the millilitre and litre, the cubic metre, the cubic inch and the cubic foot. The US dry gallon is not in the table, so a dry measure needs converting elsewhere rather than assuming this one fits.

Is anything I type uploaded?

Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account. This focused page opens on Gallon (imperial) and Cubic meter, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen.

Gallons to Cubic Meters (gal to m³)

Gallons to cubic metres depends on which gallon you have, and both sizes are exact by definition rather than measured: the imperial gallon is exactly 4.54609 litres, so 0.00454609 m³, and the US liquid gallon is 231 cubic inches, which is exactly 3.785411784 litres, so 0.003785411784 m³. The imperial gallon is the larger by about a fifth, since 1 imperial gallon is 1.2009499255 US gallons and 1 US gallon is 0.832674184629 imperial gallons. This page opens the converter with Gallon (imperial) in the From box and Cubic meter in the To box, ahead of whatever pair you last used, so 1 gallon reads 0.00454609 m³, 100 gallons reads 0.454609 m³ and 1,000 gallons reads 4.54609 m³, while picking Gallon (US) in the same menu switches to the American one, where 100 gallons is 0.3785411784 m³ and 1,000 gallons is 3.785411784 m³. Under the answer the same volume is listed in millilitres, litres, cubic metres and the US kitchen units at once, so one imperial gallon shows as 4,546.09 mL, 4.54609 L and 1.2009499255 US gallons, and the Show 5 more switch adds the imperial fluid ounce, the imperial pint, the cubic inch and the cubic foot: 160 imperial fluid ounces, 8 imperial pints, 277.419432792 in³ and 0.160543653236 ft³.

From

To0.00454609

Category: Volume

Base unit: liter

Uncommon units: Show 5 more

Spoons and cups are US customary measures. Imperial fluid ounces, pints and gallons have separate labeled entries; metric and Australian spoons are not separate units.

Results round to 12 significant digits using the listed unit definitions. Input must have a finite numeric magnitude and at most 512 significant digits. Type a single decimal or scientific number; a matching From unit suffix is accepted. Commas and grouped spaces separate thousands; decimal commas, fractions and compound measurements are refused.

1 gal in every volume unit

MillilitermL
4,546.09
LiterL
4.54609
Cubic meterm³
0.00454609
Teaspoon (US)tsp
922.329542788
Tablespoon (US)tbsp
307.443180929
Fluid ounce (US)fl oz
153.721590465
Cup (US)cup
19.2151988081
Pint (US)pt
9.60759940404
Quart (US)qt
4.80379970202
Gallon (US)gal
1.2009499255

Selectable complete conversion

Unit Converter — Volume
Input: 1 (Gallon (imperial), gal)
Result: 0.00454609 m³ (Cubic meter)
Displayed values round to 12 significant digits.
Spoons and cups are US customary measures. Imperial fluid ounces, pints and gallons have separate labeled entries; metric and Australian spoons are not separate units.
All other units:
Milliliter (mL): 4546.09
Liter (L): 4.54609
Cubic meter (m³): 0.00454609
Teaspoon (US) (tsp): 922.329542788
Tablespoon (US) (tbsp): 307.443180929
Fluid ounce (US) (fl oz): 153.721590465
Cup (US) (cup): 19.2151988081
Pint (US) (pt): 9.60759940404
Quart (US) (qt): 4.80379970202
Gallon (US) (gal): 1.2009499255
Fluid ounce (imperial) (fl oz): 160
Pint (imperial) (pt): 8
Cubic inch (in³): 277.419432792
Cubic foot (ft³): 0.160543653236

Common questions

How many cubic meters are in a gallon?: One imperial gallon is exactly 0.00454609 m³ and one US liquid gallon exactly 0.003785411784 m³, using their definitions of 4.54609 L and 231 international cubic inches respectively. The cross-system ratio is not a terminating decimal: 1 imperial gallon displays as 1.2009499255 US gal and 1 US gal as 0.832674184629 imperial gal. The exact definitions are retained, while outputs round to twelve significant digits.
What is the formula for gallons to cubic meters?: m³ = imperial gallons × 0.00454609, or m³ = US gallons × 0.003785411784. Both come from the litre, which is this converter's base unit for volume: a cubic metre is exactly 1,000 litres, so a gallon in litres divided by 1,000 is the same gallon in cubic metres. Reversed, one cubic metre is 219.969248299 imperial gallons or 264.172052358 US gallons.
Worked example: what is 100 gallons in cubic meters?: 100 imperial gallons is 0.454609 m³ and 100 US gallons is 0.3785411784 m³. The same factors give: 5 imperial gallons is 0.02273045 m³, 50 is 0.2273045 m³, 500 is 2.273045 m³ and 1,000 is 4.54609 m³. In US gallons, 1,000 is 3.785411784 m³.
Which gallon is my figure in?: Use the source’s explicit definition or documented unit convention. A bare gallon label does not establish whether it means US liquid, imperial or a separate dry measure. This page opens on the imperial gallon of exactly 4.54609 L and offers the US liquid gallon of exactly 3.785411784 L in the same From menu. Changing From reinterprets the typed scalar quantity. The US gallon readout for 1 imperial gallon displays as 1.2009499255 US gal; it does not identify the convention of an external label.
How do I convert cubic meters back to gallons?: Press the swap button between the two boxes and the page runs cubic metres into imperial gallons: 1 m³ is 219.969248299 gallons, 0.5 m³ is 109.98462415 gallons and 10 m³ is 2,199.69248299 gallons. The same cubic metre is 264.172052358 US gallons once you pick Gallon (US) in the To menu. Swap keeps the number you typed rather than the answer, so it converts that figure in the new direction.
Is a cubic metre the same as 1,000 litres?: Yes, exactly, and the converter is built that way: the litre is the base unit for volume here and the cubic metre carries a factor of exactly 1,000. So 1 m³ is 1,000 L, 1 L is 0.001 m³, and an imperial gallon of 4.54609 L becomes 0.00454609 m³ with the decimal point moved three places. A US gallon of 3.785411784 L becomes 0.003785411784 m³ the same way.
Why did a small number come back as 4.54609e-7?: Because anything below 0.000001 is printed in exponential notation rather than as a row of leading zeros. 0.0001 imperial gallons is 4.54609e-7 m³, while 0.1 gallons stays decimal at 0.000454609 m³. At that size the friendlier rows are already in the list underneath: 0.1 imperial gallons is 0.454609 L and 454.609 mL.
Does it know the US dry gallon?: No. The volume menu holds one US gallon, the liquid one of 231 cubic inches, next to the imperial gallon, US teaspoons, tablespoons, fluid ounces, cups, pints and quarts, the millilitre and litre, the cubic metre, the cubic inch and the cubic foot. The US dry gallon is not in the table, so a dry measure needs converting elsewhere rather than assuming this one fits.
Is anything I type uploaded?: Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account. This focused page opens on Gallon (imperial) and Cubic meter, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen.

Results round to 12 significant digits using the listed unit conventions. Many factors are exact definitions; psi and parsec use rounded coefficients. Temperature includes scale offsets. Days and weeks are fixed-duration units, and unit conversion does not determine calendar dates, ambient pressure or a software label’s convention.