Volume · Unit Converter

Convert Imperial Teaspoon to Milliliter

Convert imperial teaspoons to milliliters instantly. 1 imperial teaspoon = 5.9193880208 milliliter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Milliliter to Imperial Teaspoon converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Jaya Christiyan K G, Ph.D.
Volume category 2 min read Published Last reviewed Updated

Units explained

Imperial (UK)

Imperial Teaspoon

What is a imperial teaspoon?

An imperial teaspoon is about 5.9194 mL, one third of an imperial tablespoon.

Origin of the imperial teaspoon

A British cooking measure.

Where it is used

Older UK recipes.

When and where it was developed

UK cooking measure.

Metric / SI

Milliliter

What is a milliliter?

A milliliter is one thousandth of a liter, exactly equal to one cubic centimeter.

Origin of the milliliter

Formed with the SI prefix milli- applied to the liter.

Where it is used

The standard small-volume unit in cooking, medicine and the laboratory.

When and where it was developed

Metric prefix system.

Imperial Teaspoon to Milliliter conversion formula

The relationship between imperial teaspoons and milliliters:

1 tsp = 5.9193880208 mL
1 mL = 0.1689363827 tsp

To convert imperial teaspoons to milliliters, multiply the value in imperial teaspoons by 5.9193880208. To reverse, multiply milliliters by 0.1689363827.

How to use this converter

Type a value into the calculator. The result in milliliters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Milliliter to Imperial Teaspoon converter for the reverse direction.

Step-by-step: convert imperial teaspoons to milliliters

  1. Write down the value in imperial teaspoons (tsp).
  2. Multiply that value by the factor 5.9193880208.
  3. The product is the equivalent value in milliliters (mL).
  4. To reverse, multiply the milliliter value by 0.1689363827.

Worked examples

Example 1 — Convert 1 tsp to mL:
1 × 5.9193880208 = 5.9193880208 mL

Example 2 — Convert 100 tsp to mL:
100 × 5.9193880208 = 591.9388020833 mL

Real-world example — Plastic-film thickness alternates

A 150-imperial teaspoon plastic film converts cleanly to milliliters — useful for packaging buyers reconciling supplier datasheets across metric and US measurement systems.

150 tsp × 5.9193880208 = 887.908203125 mL

Real-world example — Hair-width scale measurements

A 70-imperial teaspoon measurement (about the diameter of a human hair) is the kind of value materials engineers regularly express in adjacent micro-scale units like milliliters for direct comparison across supplier datasheets.

70 tsp × 5.9193880208 = 414.3571614583 mL

Real-world example — Paper and film thicknesses

At the thickness of office paper (roughly 3 imperial teaspoons), converting between sub-millimeter units is routine for packaging and printing buyers comparing quotes from metric and US suppliers.

3 tsp × 5.9193880208 = 17.7581640625 mL

Imperial Teaspoon to Milliliter conversion table

Standard reference values for converting imperial teaspoons to milliliters:

Imperial Teaspoon [tsp]Milliliter [mL]
0.010.0591938802
0.10.5919388021
15.9193880208
211.8387760417
317.7581640625
423.6775520833
529.5969401042
1059.1938802083
20118.3877604167
30177.581640625
40236.7755208333
50295.9694010417
100591.9388020833
5002959.6940104167
10005919.3880208333

Frequently asked questions

How many milliliters is 1 imperial teaspoon?
1 imperial teaspoon equals 5.9193880208 milliliter.
How do I convert imperial teaspoons to milliliters?
Multiply the value in imperial teaspoons by 5.9193880208 to get milliliters.
How do I convert milliliters back to imperial teaspoons?
Multiply the value in milliliters by 0.1689363827, or use the Milliliter to Imperial Teaspoon converter.
How many milliliters is 100 imperial teaspoons?
100 imperial teaspoons equals 591.9388020833 milliliters, because 100 × 5.9193880208 = 591.9388020833.

Convert Imperial Teaspoon to other volume units

Show all Imperial Teaspoon conversions

Sources & references

Conversion factor (1 tsp = 5.9193880208 mL) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.