Metric Teaspoons to Cubic Inches (tsp to in³)

1 metric teaspoon equals 0.3051187205 cubic inches (rounded).

1 metric teaspoon = 0.3051187205 cubic inches

How to convert metric teaspoons to cubic inches

To convert metric teaspoons to cubic inches, multiply the number of metric teaspoons by 0.3051187205. The factor is rounded to 10 significant digits. To go the other way, multiply cubic inches by 3.2774128.

cubic inches = metric teaspoons × 0.3051187205

Example: 10 metric teaspoons = 3.051187205 cubic inches.

Pints, quarts, gallons and fluid ounces differ between the US and the UK. Units are labeled 'US' or 'imperial' to avoid confusion.

About these units

Metric Teaspoon (tsp)

Cooking & barCurrent unit

Exactly 5 mL, used in most countries.

Five milliliters is the metric teaspoon, a figure so tidy that it has become the working definition for medicine and food labels. The traditional British teaspoon was an imperial fluid drachm, one eighth of an imperial fluid ounce, about 3.55 milliliters, and the American one was 4.93 mL. US nutrition labeling law now defines a teaspoon as exactly 5 milliliters.

The 5 mL teaspoon matters most when dosing medicine. Kitchen spoons vary widely, with one Greek survey of 71 household teaspoons finding volumes from 2.5 to 7.3 mL, so measuring spoons, syringes and calibrated cups are the safer tools. It also anchors the metric cooking system: three teaspoons make a 15 mL tablespoon, and fifty fit in a 250 mL metric cup. Australia keeps a 5 mL teaspoon but counts four of them in its larger 20 mL tablespoon.

1 metric teaspoon = 0.005 liters (exactly).

Sources: Wikipedia: Teaspoon; 21 CFR 101.9: nutrition labeling household measures; Wikipedia: Metric cup

Cubic Inch (in³)

US & ImperialCurrent unit

Exactly 16.387064 mL. Used for engine displacement in the US and for small mechanical parts.

Cubic inch is a unit defined by a ruler. Take an inch, build a cube, and its volume is exactly 16.387064 milliliters under the modern definition of the inch as 25.4 millimeters. Its main role in history is as the building block behind other US volumes: the US gallon is defined as 231 cubic inches, so a cubic inch is exactly 1/231 of a gallon. Even the 42-gallon oil barrel works out to precisely 9,702 of them.

The cubic inch survives most visibly in American engines, which are abbreviated c.i.d. for cubic inch displacement, while the rest of the world and many modern automakers speak in liters. A 5.7 liter engine is about 350 cubic inches, a conversion made easy by the exact factor of 16.387064. Small mechanical parts are also sized in cubic inches in North America.

1 cubic inch = 0.016387064 liters (exactly).

Sources: Wikipedia: Cubic inch; NIST SP 811, Appendix B.8: conversion factors for volume

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