The distilling math you reach for most — ABV from gravity, dilution to bottle strength, sugar bills, recovery, pure alcohol — all free, all in your browser, no account needed.
Most online dilution calculators give you the wrong answer because they assume volumes are additive. They aren't — mixing ethanol and water contracts measurably. Broover's dilute-to-target calculator uses the OIML R22-1975 density tables so the volume you measure in the bottle matches the strength you punched in. Drop in your starting volume and ABV, choose the target ABV, and Broover gives you the exact volume of water to add.
Convert OG and FG into ABV using the Hall formula — accurate across the full distillery wash range (5–25% ABV) where the textbook linear approximation systematically underestimates above 7%. Plus a wash-side calculator for predicting final ABV from a measured original gravity at target finish gravity 0.995. Pair with the contraction-aware dilution above to get from kettle to bottle without the back-of-an-envelope errors.
Sugar bill from target OG and volume; charge volume from your still's boiler capacity and headspace allowance; recovery prediction from your strip-run or spirit-run efficiency. The numbers you'd otherwise be looking up in a dozen forum threads, in one screen.
All calculators are public — no signup, no card. Bookmark the page and use it like a spreadsheet, just faster. See how Broover works if you want the full workflow app — recipes, washes, distillation runs, lots, RAPT Pill integration, all tied together with provenance.
Enter your starting volume and ABV, then your target ABV — the dilution calculator returns the exact volume of water to add. It uses the OIML R22-1975 ethanol-water density tables, so it accounts for contraction (ethanol and water don't add to the sum of their volumes). That's why the strength you measure in the bottle matches the number you typed.
Most assume volumes are additive — add 1 L of water to 1 L of spirit and you get 2 L. You don't: the mixture contracts measurably, so a naive calculator tells you to add too much water and you finish under strength. Broover corrects for contraction using the official OIML R22 density tables.
Enter original gravity (OG) and final gravity (FG). Broover uses the Hall formula, accurate across the 5–25% ABV range typical of distilling washes — the textbook linear (OG−FG)×131.25 approximation under-reads above about 7% ABV.
Pure alcohol litres (LPA / PA L) = volume × ABV. Enter a volume and its ABV and the pure-alcohol calculator returns the absolute ethanol content — the figure you track for yield, excise, and blending.
The strip-run and spirit-run planners estimate expected output volume and ABV from your charge volume, charge ABV, and still efficiency, so you can plan cuts and bottle counts before you fire the boiler.
Yes — every calculator is free and public, no signup and no card. They run entirely in your browser; nothing is sent to a server.
Deep dives: the alcohol dilution calculator (why contraction matters), the ABV-from-specific-gravity calculator (the Hall formula), and the sugar wash calculator (sugar bill + expected ABV).