Hot Sauce Dilution Calculator

Estimate the SHU rating of a sauce after blending it with a milder diluent.

What it does

Scoville Heat Units measure capsaicinoid concentration, and concentration follows volume. Blend a strong sauce into a mild one and the heat lands between the two in exact proportion to the volumes.

The tool above takes the starting sauce, its rating, and the diluent amount, then returns the blended SHU, the ratio, and the total volume. The default blend, 2 fl oz of 1,000,000 SHU sauce into 6 fl oz of diluent, lands at 250,000 SHU.

The math is linear because capsaicinoids are conserved: nothing destroys them in simple mixing. New Mexico State University publishes the working figure behind SHU, one part per million of capsaicin reads about 16 SHU, which is how lab assays translate into the numbers on labels.

Perceived heat does not fall as fast as the math suggests. Sugar, fat, and acid mask burn, and vinegar thins texture, so a blended sauce often tastes hotter than its rating or milder than expected depending on what the diluent brings.

For home cooking this page is a planning tool: stretch a bottle, tame a gift sauce for a crowd, or lay out a wing sauce ladder. Food safety sits outside the math, so remember that adding fresh garlic or fruit shortens shelf life regardless of SHU.

How to use

1. Pick fluid ounces or milliliters.
2. Enter the volume of hot sauce going in.
3. Enter its label or reference SHU rating.
4. Enter the volume of diluent.
5. Read the blended rating and the ratio.
6. Taste a spoonful before committing the whole batch.

Formula

SHU

Rating of the starting sauce, from the label or a published table.

sauce

Volume of the hot sauce in the blend.

diluent

Volume of the milder liquid, or zero for no dilution.

One part per million of capsaicin equals roughly 16 SHU, which anchors lab ratings. The blend math only conserves capsaicinoids; it assumes both parts mix completely. A blend with zero diluent keeps the original rating, and the ratio line shows 1 to 0 for that case. Fresh add-ins change shelf life, not SHU.

Worked example

Reference table

Limits

• Predicts rating, not taste. Sugar, fat, and acid shift perceived heat.
• Assumes complete mixing; layered pours do not blend on their own.
• Fresh add-ins change food safety and shelf life, which SHU math ignores.
• Below about 1,000 SHU most tasters stop telling the difference.

Common mistakes

• Averaging the two SHU labels instead of weighting by volume.
• Adding diluent by eye, then wondering why the batch still burns.
• Expecting a linear drop in perceived heat to match the linear drop in SHU.
• Using sweet diluents and tasting only at the start, before the sugar dissolves.
• Diluting with plain water, which flattens flavor without fixing the burn.

Try it yourself

Quick checks. Answers sit tucked under each question.

Questions

Sources

• New Mexico State University: hot pepper pungency and SHU (H-237)
• Penn State Extension: growing hot peppers and how heat works

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