Metric vs US Tablespoon: Understanding the Difference
Learn the key differences between metric and US tablespoons, when it matters, and how to convert between the two standards for accurate cooking and baking.
The Two Tablespoon Standards
Not all tablespoons are created equal. Depending on where you are in the world, a “tablespoon” can mean different things:
- Metric Tablespoon: Exactly 15 ml (used in most countries)
- US Tablespoon: Approximately 14.79 ml (technically 14.7868 ml)
- Australian Tablespoon: 20 ml (the outlier!)
Why the Difference Exists
The metric system was designed for simplicity and consistency. A metric tablespoon is exactly 15 milliliters — clean, simple, and mathematically convenient.
The US tablespoon derives from older English measurements. It’s defined as exactly half a US fluid ounce (1/2 fl oz), which works out to approximately 14.7868 ml.
Does the Difference Matter?
The difference between a metric and US tablespoon is about 1.4%. Whether this matters depends on what you’re making:
When it doesn’t matter much:
- Everyday cooking (soups, stews, sauces)
- Adding spices or seasonings
- Measuring liquids for drinking
- Most home cooking situations
When it can matter:
- Precision baking (especially at scale)
- Leavening agents (baking powder, baking soda)
- Concentrated ingredients (vanilla extract, salt)
- Professional recipe development
- Scientific applications
Practical Examples
Let’s see the difference with some common ingredients:
| Ingredient | 1 Metric tbsp (g) | 1 US tbsp (g) | Difference |
|---|---|---|---|
| Water | 15.00 | 14.79 | 0.21g |
| Sugar | 12.75 | 12.57 | 0.18g |
| Flour | 7.95 | 7.84 | 0.11g |
| Salt | 18.30 | 18.04 | 0.26g |
| Butter | 14.40 | 14.20 | 0.20g |
For a single tablespoon, the differences are tiny. But they compound — if a recipe calls for 10 tablespoons of flour, the difference grows to about 1.1 grams, which is still relatively small.
How to Know Which Standard to Use
Check where the recipe comes from:
- US cookbook or website → US tablespoon
- European, Asian, or international → Metric tablespoon
- Australian → 20 ml tablespoon (be careful!)
When in doubt, use metric. It’s the international standard and the difference is small enough that it rarely causes problems.
The Best Solution: Weigh in Grams
The whole metric-vs-US debate becomes irrelevant when you measure by weight. Grams don’t change based on geography.
This is why professional bakers worldwide use scales and gram measurements. Our converter supports both standards so you can get accurate gram weights regardless of which tablespoon type your recipe uses.
Quick Conversion
To convert between the two:
- Metric to US: multiply by 0.9858
- US to Metric: multiply by 1.0144
Or just use our calculator — it handles this automatically with a simple toggle!