Temperature Correction
Correct a hydrometer proof reading taken at a non-60 °F temperature to its true proof at 60 °F (27 CFR §30.61, Table 1).
Calculator
Enter your hydrometer proof reading and the temperature you took it at to see the true proof corrected to 60 °F.
Enter a reading and a temperature to see the result.
This is a quick estimate for reference — a tool, not an official TTB filing or gauge record. It computes the true percent of proof for your reading at the observed temperature per 27 CFR §30.61 Table 1 (from the OIML ethanol-water density model).
Correcting a GRAVITY reading, not a proof reading?
- Gravity Temperature Correction — your hydrometer reads specific gravity (1.048, not 96° proof) — a wort, must or juice sample. That is a different correction with a different formula; this page’s §30.61 method does not apply to it.
Reference tools, not a system of record. These free calculators are provided for convenience and general reference only. They are not a system of record and must not be used as the basis for any TTB or state compliance filing — even when a result is correct. Your official filings are governed by the applicable measurement and gauging methods and by your own production records.