Teaspoons to Millilitres Converter

Convert teaspoons to ml instantly. 1 US teaspoon = 4.929 ml. Quick reference for ½ tsp, 1 tsp, 2 tsp and more.

Result

4.93 ml

Understanding Teaspoons to Millilitres

One US teaspoon equals exactly 4.929 millilitres (often rounded to 5ml). This is a fixed conversion because both measure volume. However, UK teaspoons are 5.919ml (about 20% larger), and metric teaspoons are exactly 5ml. Australian teaspoons are also 5ml. The difference between US and UK teaspoons can significantly affect recipes with multiple teaspoon measurements.

When to Use Teaspoons to Millilitres

Working with recipes from different countries? Converting teaspoons to millilitres is useful when you need precise liquid measurements. Teaspoons are commonly used in American and British recipes, while millilitres are standard in metric countries. This conversion is essential for medicine dosing, cocktails, and precise flavouring.

Practical Tips

This conversion is most useful for liquids like vanilla extract, lemon juice, or oil, where the measurement is straightforward. It's also helpful when you have measuring spoons marked in teaspoons but need millilitre equivalents, or when following international recipes. For most purposes, treating 1 teaspoon as 5ml is accurate enough.

Quick Tips

  • 1 US teaspoon = 4.929ml (approximately 5ml)
  • UK teaspoons are slightly larger at 5.919ml
  • Metric teaspoons are exactly 5ml
  • This conversion works perfectly for all liquids since both measure volume

Common Mistakes to Avoid

The most common error is assuming all teaspoons are the same size. US teaspoons (4.929ml) and UK teaspoons (5.919ml) differ by about 20%. Using UK teaspoons when a US recipe calls for teaspoons would give you 20% more of each ingredient. Another mistake is using household spoons instead of measuring spoons — regular teaspoons vary widely in size.

When Precision Matters

Precision matters for medicine dosing (always use the provided measuring device), cocktails where flavour balance is critical, and when measuring expensive ingredients like vanilla extract or saffron. For cooking, the difference between 4.929ml and 5ml rarely matters. For baking with leavening agents, consider converting to grams instead.

Quick Reference

1 US tsp = 4.929ml
Often rounded to 5ml
1 UK tsp = 5.919ml
About 20% larger than US
1 metric tsp = 5ml
The international standard
3 tsp = 1 tbsp
Universal ratio regardless of system

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Related Conversions

Teaspoons to Millilitres Reference Table

teaspoonsmillilitres
0.25 tsp1.23 ml
0.5 tsp2.46 ml
1 tsp4.93 ml
1.5 tsp7.39 ml
2 tsp9.86 ml
3 tsp14.8 ml
4 tsp19.7 ml
5 tsp24.6 ml
10 tsp49.3 ml
25 tsp123 ml
50 tsp246 ml
100 tsp493 ml

Frequently Asked Questions

How many ml in a teaspoon?
It depends on which teaspoon you mean. A US teaspoon is 4.929ml (often rounded to 5ml). A UK teaspoon is 5.919ml. A metric teaspoon is exactly 5ml. For most cooking purposes, treating 1 teaspoon as 5ml is accurate enough, but be aware of the differences for precision work.
Why are UK teaspoons larger than US teaspoons?
Historical measurement systems developed independently. The UK teaspoon (5.919ml) evolved from traditional British measures, while the US teaspoon (4.929ml) came from different historical standards. When the UK partially metricated, they didn't fully standardise teaspoon sizes, leading to the current 20% difference.
Should I round 4.929ml to 5ml?
For most cooking purposes, yes. The 1.4% difference rarely affects results. However, for medicine dosing, always use the exact measurement or the provided measuring device. For cocktails or when scaling recipes significantly, the small difference can compound, so use 4.929ml for accuracy.
Is the teaspoons-to-ml conversion the same for all ingredients?
Yes, because both teaspoons and millilitres measure volume. Unlike weight conversions (which depend on density), 1 teaspoon of water, vanilla extract, or honey all equal the same number of millilitres. However, they weigh different amounts in grams due to their different densities.

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