Is my data private with SipLogger?

Yes, SipLogger has no backend servers, requires no account, and collects no data. All your drink logs and session history stay entirely on your device. HealthKit data (weight, height, sex, age) is read-only and never leaves your device. The app contains no analytics, no tracking, and no third-party SDKs.

SipLogger — Educational BAC Calculator & Drink Tracker

Understand Alcohol Metabolism. Visualize Your Estimated BAC Curve.

Educational and informational BAC estimation tool for iPhone & iPad. No account. No ads. No data collection.

For educational & informational purposes only. Rated 18+.

SipLogger is a free educational and informational tool that helps you understand how alcohol metabolism works. Visualize your estimated blood alcohol content (BAC) over time using the Watson Total Body Water method and the Widmark formula — established pharmacokinetic models personalized by your weight, height, sex, and age. Choose from 40+ built-in drink templates or create custom entries. Observe how drink pace and timing affect your estimated BAC curve, review session history, and learn from your patterns — all with HealthKit integration and Live Activities for at-a-glance monitoring. No subscription. No ads. No account. No data collection. All BAC values are estimates with approximately +/-20% variance. For educational and informational purposes only. Available in 8 languages with metric and imperial support.

See the Educational BAC Calculator in Action

SipLogger active session — real-time estimated BAC tracking with drink timeline and metabolism curve

SipLogger estimated BAC chart — visualize alcohol metabolism over time with Widmark formula

SipLogger add drink — choose from 40+ built-in drink templates with custom volume and ABV

SipLogger session history — review past drinking sessions and estimated BAC patterns

Educational BAC Estimation — Key Features

Educational Estimated BAC Curve

View your estimated blood alcohol content as a smooth chart over time. Observe estimated absorption, peak, and metabolism phases — designed to help you understand how alcohol affects the body. All values are approximations (+/-20%).

Watson + Widmark Formulas

Uses the Watson Total Body Water method combined with the Widmark formula for scientifically-grounded estimation. Personalized by weight, height, biological sex, and age. All values are approximations (+/-20%).

40+ Built-In Drinks

Choose from a curated library of 40+ drink templates — beer, wine, spirits, cocktails, and more. Each has pre-configured volume and ABV. Create custom drinks with any volume and alcohol percentage.

Drink Pace Modeling

Each drink's estimated absorption is modeled individually based on timing. Observe how spacing may affect your estimated BAC curve — for educational understanding only.

HealthKit Integration

Optionally read weight, height, biological sex, and age from Apple HealthKit for more accurate educational estimates. Read-only — SipLogger never writes to HealthKit and never transmits your health data.

Session History & Diary

Review past sessions with detailed drink logs, estimated peak BAC, session duration, and time to approach baseline. A personal educational diary of your drinking patterns.

Live Activities

Monitor your active session from the Lock Screen and Dynamic Island with Live Activities. See your current estimated BAC and time to approach baseline at a glance.

8 Languages

Available in English, Ukrainian, Polish, French, Spanish, German, Czech, and Italian. Full localization with metric and imperial measurement support.

How the Educational BAC Calculator Works

Set Up Your Profile

Enter your weight, height, sex, and age — or let SipLogger read them from HealthKit. These values personalize the Watson + Widmark formula.

Log Your Drinks

Pick from 40+ templates or create custom drinks. Each drink is timestamped for accurate absorption modeling in the estimated BAC calculation.

Review Your Sessions

See your estimated BAC curve, review session history, and learn how different drinking patterns affect estimated alcohol metabolism.

Why SipLogger Is Completely Free

No Subscription, No Ads

SipLogger is 100% free with no subscription, no ads, no in-app purchases, and no hidden costs. Every feature is available from day one.

Complete Privacy

No backend servers. No account required. No analytics in the app. All data stays on your device. Your drinking data is nobody's business but yours.

Educational Mission

SipLogger exists as an educational and informational tool to help people understand alcohol metabolism. Knowledge promotes responsible decision-making.

Metric & Imperial

Switch between measurement systems based on your preference — milliliters or fluid ounces, kilograms or pounds.

⚠️ Important Disclaimer

SipLogger is strictly an educational and informational tool. It does not measure actual blood alcohol content. All BAC values are mathematical estimates with approximately +/-20% variance that can differ significantly from actual BAC based on food intake, hydration, medications, liver function, genetics, and other individual factors. Never use this app to determine whether it is safe to drive, operate machinery, or engage in any activity requiring full alertness. Always err on the side of caution. If you have consumed alcohol, use a certified breathalyzer device or arrange alternative transportation. This app does not encourage, promote, or endorse alcohol consumption. Intended for adults of legal drinking age only. Rated 18+.

Frequently Asked Questions

Is SipLogger really free?

Yes, SipLogger is 100% free with no subscription fees, no ads, and no in-app purchases. It is an educational tool for understanding alcohol metabolism. All features are available immediately with no restrictions.

How does the estimated BAC calculation work?

SipLogger uses the Watson Total Body Water (TBW) method combined with the Widmark formula to estimate blood alcohol content. The calculation considers your weight, height, biological sex, and age to model how alcohol is absorbed and metabolized over time. Results are educational estimates with approximately ±20% accuracy.

How accurate is the estimated BAC?

The estimated BAC has approximately ±20% accuracy. Individual metabolism varies based on many factors including food intake, hydration, medications, liver health, and genetics. SipLogger is for educational and informational purposes only — never use estimated BAC to make decisions about driving or operating machinery.

Does SipLogger tell me when I can drive?

No. SipLogger is an educational tool and never provides driving advice. The app shows when your estimated BAC approaches baseline levels, but this should never be used to determine fitness to drive. Always use a certified breathalyzer or wait a safe amount of time. When in doubt, use a taxi or rideshare.

Is my data private?

Yes, SipLogger has no backend servers, requires no account, and collects no data. All your drink logs and session history stay entirely on your device. HealthKit data is read-only and never leaves your device. The app contains no analytics, no tracking, and no third-party SDKs.

What HealthKit data does SipLogger use?

SipLogger optionally reads weight, height, biological sex, and date of birth from HealthKit to improve estimated BAC accuracy. This data is only used locally for calculations — it is never transmitted, stored externally, or shared. SipLogger never writes data to HealthKit.

How many drinks are in the built-in database?

SipLogger includes 40+ built-in drink templates covering beer, wine, spirits, cocktails, and more. Each template has pre-configured volume and alcohol percentage. You can also create custom drinks with any volume and ABV percentage.

What is the Widmark formula?

The Widmark formula is a well-established pharmacokinetic model for estimating blood alcohol content. It calculates estimated BAC based on the amount of alcohol consumed, body weight, a gender-specific distribution ratio, and time elapsed. SipLogger enhances this with the Watson Total Body Water method for improved body water estimation, making it a reliable educational tool.

Does SipLogger work on iPad?

Yes, SipLogger is a universal app that works on both iPhone and iPad. The interface adapts to larger screens for a comfortable experience on iPad.

What is the age rating for SipLogger?

SipLogger is rated 18+ on the App Store. The app is intended for adults of legal drinking age. It is an educational and informational tool — it does not encourage or promote alcohol consumption.

Your Privacy Is Absolute

No account required. No backend servers. No analytics. No data collection. All your drink logs and session data stay on your device. HealthKit data is read-only and never transmitted. SipLogger is a completely private, educational tool.