Coffee TDS & Extraction Yield Calculator
Use this tool to calculate brew ratio, dissolved solids, and extraction yield from your refractometer reading.
Formula used: Extraction Yield (%) = (Beverage Weight × TDS%) ÷ Coffee Dose
What is a coffee TDS calculator?
A coffee TDS calculator helps you turn brewing data into useful feedback. TDS means Total Dissolved Solids: the percentage of coffee material dissolved into your drink. Once you combine TDS with coffee dose and beverage mass, you can estimate extraction yield, which tells you how much of the coffee grounds were extracted.
In practical terms, this is how you move from “this tastes off” to “this brew is under-extracted and slightly weak.” For home brewers, café staff, and competition-level enthusiasts, TDS data can make your recipe adjustments faster and far more consistent.
Strength vs extraction: the two numbers that matter
1) Strength (TDS)
TDS describes how concentrated your coffee is. A low TDS often tastes thin or watery. A high TDS often tastes heavier and more intense.
2) Extraction Yield (EY)
Extraction yield estimates how much soluble material you pulled from the grounds. Very low extraction can taste sour, salty, or hollow. Very high extraction can taste dry, bitter, and astringent.
These two numbers interact. You can have coffee that is strong but under-extracted, or weak but over-extracted. That is why good coffee control requires both.
Reference ranges for common brew styles
| Brew Style | Typical TDS Range | Typical EY Range | Common Brew Ratio |
|---|---|---|---|
| Filter / Pour Over | 1.15% – 1.45% | 18% – 22% | 1:15 to 1:18 |
| Immersion | 1.20% – 1.50% | 18% – 22% | 1:14 to 1:17 |
| Espresso | 8% – 12% | 18% – 22% | 1:1.8 to 1:2.5 |
How to use this calculator correctly
- Measure your dry coffee dose in grams.
- Brew and record final beverage mass (not just water poured).
- Take a refractometer reading and enter TDS.
- Optionally enter water used to estimate retained water in the coffee bed.
- Click calculate and use the recommendations to adjust your next brew.
How to interpret the output
If extraction is low (<18%)
- Grind finer
- Increase contact time
- Raise brew temperature slightly
- Improve agitation or flow distribution
If extraction is high (>22%)
- Grind coarser
- Shorten contact time
- Lower brew temperature slightly
- Reduce agitation
If strength (TDS) is too low
- Use more coffee for the same beverage weight
- Use less brew water or lower yield
If strength (TDS) is too high
- Use slightly less coffee
- Increase beverage yield
Common mistakes when measuring TDS
- Not calibrating the refractometer
- Testing coffee that is too hot for accurate readings
- Inconsistent stirring before sample extraction
- Entering brew water instead of beverage mass in cup
- Changing multiple brew variables at once
Why this matters for consistency
Great coffee is repeatable coffee. A TDS calculator gives you a simple system: brew, measure, adjust, repeat. Over time, you can build method-specific targets for each coffee and roast level. This is especially useful when dialing in new beans, training baristas, or comparing equipment.
Keep a log of dose, ratio, grind setting, brew time, TDS, and extraction. In just a few sessions, you will spot patterns and make sharper decisions with less guesswork.