# True Proof > Calculates true proof of water-alcohol mixtures and performs gauging calculations. (iPhone/iPad app by Greg Miller.) - Source: https://appshunter.io/ios/app/true-proof/id901015790 (this page in markdown: same URL + `.md`) - Developer: [Greg Miller](https://appshunter.io/developer/901015793) - Category: Utilities, Business - Price: $9.99 - Rating: 4.00/5 from 4 App Store ratings · 3 written reviews indexed - Age rating: 17+ - Requires: iOS 12.0 · 8 MB - Languages: American English - Released: 2014-08-05 - Data updated: 2026-06-28 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/true-proof/id901015790/reviews.md ## What is True Proof? True Proof calculates the true proof of a water-alcohol mixture at a reference temperature, using the measured apparent proof from a hydrometer reading and the temperature at the time of the reading. True Proof also performs gauging calculations, and can calculate dilutions taking full account of the temperature-dependent nonideal mixing of water and alcohol. Calculations are logged, and may be annotated and emailed for archiving. Multiple units support large-scale distillers and hobby-scale distillers alike, in the US and abroad: concentration measurement in proof, ABV, or density ; temperature in °F or °C; abundance in US gallon, liter, pound, kg, US ton, or metric tonne, etc. The reference temperature can be selected for US (60ºF) or international (20ºC), or any other value in the range [-20ºC,40ºC]. The instrument thermal expansivity can be selected, which enables application to vibrating tube densitometers in addition to hydrometers. Two separate computational models are employed - one based on the (US) TTB gauging manual, and one based on OIML (UK, EU, Canada, etc) data. The computer model is limited in temperature and proof range to that spanned by government standard tables. ## Key features - True proof calculation - Gauging calculations - Dilution calculations - Temperature compensation - Log and email results - Multiple unit support ## Recent user reviews (3 of 3) All indexed reviews: https://appshunter.io/ios/app/true-proof/id901015790/reviews.md ### 5/5 — Perfect Handheld App! *2018-04-04* As a professional distiller, I have to constantly stop and calculate the proof of the product multiple times during the day. This app is great; it’s quick and easy to calculate proof on the fly while working and not have to interrupt your work constantly to figure it out longhand or leave the production area to do it on a computer. Love it. ### 5/5 — TRUE Genius *2015-03-14* Great app. It's going to make figuring out how potent my moonshine is much easier. Thank you Greg Miller. Update 3/13/15: The new update is great. The attention to detail is just what I need. ### 5/5 — 11/10 *2015-03-03* This app is the best $0.99 purchase of my life. Having bought this, I have since found fulfillment in my life and attained nirvana. Purchase to experience spiritual rebirth. ## Frequently asked questions about True Proof ### What is True Proof used for? True Proof calculates the true proof of water-alcohol mixtures using hydrometer readings and temperature. It also performs gauging calculations and dilutions, considering the temperature-dependent mixing of water and alcohol. ### How accurate is True Proof? The app uses two computational models, one based on the US TTB gauging manual and another on OIML data, to ensure accurate calculations within specified temperature and proof ranges. ### Can I save my calculations with True Proof? Yes, all calculations performed by True Proof are logged and can be annotated and emailed for archiving and record-keeping purposes. ### What units does True Proof support? True Proof supports various units for concentration (proof, ABV, density), temperature (°F or °C), and abundance (US gallon, liter, pound, kg, US ton, metric tonne), catering to both US and international users. ### What is the reference temperature in True Proof? The reference temperature in True Proof can be set to US standard (60ºF), international standard (20ºC), or any value between -20ºC and 40ºC. It also allows selection of instrument thermal expansivity. ### What devices is True Proof compatible with? True Proof is available for iPhone and iPod devices. It was last updated on October 18, 2020, with version 2.40. ### How much does True Proof cost? True Proof is a paid application, priced at $9.99. It does not feature in-app purchases or advertisements. ### What is the age rating for True Proof? True Proof has an age rating of 17+, indicating it is intended for mature users. This is likely due to the nature of alcohol-related calculations. ## Version history (last 5 releases) ### 2.40 — 2020-10-18 Quelque chose pour nos amis Seychellois - enable use of comma as decimal separator. Also bug fix, improved keyboard dismissal, change color scheme for dark mode compatibility. ### 2.35 — 2020-10-16 Quelque chose pour nos amis Seychellois - enable use of comma as decimal separator. Also bug fix and improved keyboard dismissal. ### 2.31 — 2019-04-03 When gauging by weight, volume is estimated in gallons and liters, provided the gauging proof corresponds to the last proof calculated in the proofing calculation. Improved consistency checking. ### 2.3 — 2019-04-02 Improved bounds checking, and a fix for buggy behavior near the edge of the TTB table. When gauging by weight, the fluid volume is calculated. ### 2.2 — 2018-02-27 bug fix re: ios11.2 ## Apps similar to True Proof | App | Rating | Price | Category | | --- | --- | --- | --- | | [QR Code Reader & Barcode Scan](https://appshunter.io/ios/app/qr-code-reader-and-barcode-scan/id1521174180) | 4.8 (71) | Free | Utilities | | [去电话来电话-智能发短信](https://appshunter.io/ios/app/id1513115300) | — | Free | Utilities | | [Milkplan App](https://appshunter.io/ios/app/milkplan-app/id1520251500) | — | Free | Utilities | | [戎家](https://appshunter.io/ios/app/id1515514500) | — | Free | Utilities | | [MeritAgCheck](https://appshunter.io/ios/app/meritagcheck/id1518293620) | — | Free | Utilities | | [XL Lock Manager](https://appshunter.io/ios/app/xl-lock-manager/id1516525800) | — | Free | Utilities | --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-28.*