How many cubic inches are in a teaspoon?

One US teaspoon equals approximately 0.300781 cubic inches. This comes from 1 US teaspoon = 4.92892 mL and 1 cubic inch = 16.3871 mL, so 4.92892 ÷ 16.3871 ≈ 0.300781. A metric teaspoon (5 mL) equals approximately 0.305118 cubic inches.

What is the difference between a US teaspoon and a metric teaspoon?

A US customary teaspoon is 4.92892 mL, while a metric teaspoon is exactly 5 mL. The difference is about 1.4%. For most cooking purposes they are interchangeable, but precise scientific or industrial work should specify which standard is used.

How do I convert cubic inches back to teaspoons?

Divide the number of cubic inches by 0.300781 for US teaspoons, or by 0.305118 for metric teaspoons. For example, 3 cubic inches ÷ 0.300781 ≈ 9.97 US teaspoons. You can also just type into the Cubic Inches field on this page.

Is the conversion exact?

The US teaspoon factor is derived from defined SI values (1 US fluid ounce = 29.5735295625 mL; 1 teaspoon = 1/6 fl oz) and the exact definition of the inch (1 inch = 25.4 mm exactly). The result is accurate to six significant figures for all practical purposes.

Why would I need teaspoons and cubic inches in the same calculation?

Recipes and food labels often list volumes in teaspoons, while engineers and craftspeople measure container capacity in cubic inches. Converting between them is common when designing molds, trays, or small containers intended to hold a specific number of recipe portions.

Teaspoons to Cubic Inches Converter

Convert teaspoons to cubic inches and other common volume units instantly.

Teaspoon Standard

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US Teaspoons (tsp)

Cubic Inches (in³)

Result

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Quick Reference

US Teaspoons	Cubic Inches

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Summary

This tool converts teaspoons to cubic inches and back in real time. One US teaspoon equals approximately 0.300781 cubic inches (1 US tsp = 4.92892 mL; 1 cubic inch = 16.3871 mL). Metric teaspoons (exactly 5 mL) are also supported. The tool also shows the equivalent in milliliters, tablespoons, fluid ounces, and cups for quick cross-reference.

How it works

Select US or metric teaspoon mode using the toggle at the top.
Enter a value in the Teaspoons field to convert to cubic inches.
Or enter a value in the Cubic Inches field to convert back to teaspoons.
The conversion updates instantly as you type.
Use the Swap button to flip the direction at any time.
Click Copy to copy the primary result to your clipboard.

Use cases

Verify a recipe volume when switching between cooking and engineering units.
Estimate liquid fill volume for small containers measured in cubic inches.
Cross-check ingredient measurements between metric and US customary systems.
Convert medicine dosages from teaspoons to a volumetric cubic measure.
Scale DIY or craft projects that mix volume units from different references.

Frequently Asked Questions

Last updated: 2026-06-13 · Reviewed by Nham Vu