Ethanol Calculator: Blood Alcohol, Dilution, Blending & Molar Mass
Whether you need a blood ethanol calculator for legal safety, an ethanol mix calculator for laboratory dilutions, or want to calculate the formula mass of ethanol (C₂H₅OH) for academic work, our US-optimized toolkit delivers instant accuracy. Designed for healthcare students, brewers, chemists, and automotive enthusiasts. 100% free, no sign-up.
Ethanol Dilution Calculator (Mix & Prepare Solutions)
Quickly dilute any ethanol concentration to target % using water. Perfect for 70 ethanol preparation calculator or adjusting lab reagents.
Blood Ethanol / BAC Calculator (Widmark Formula 2026)
Estimate blood ethanol level to BAC based on drinks, body weight, and time. Includes serum ethanol to BAC conversion (serum ≈ 1.2x whole blood).
*Standard drink = 14g pure ethanol (~0.6 fl oz). Serum ethanol mg/dL conversion: whole blood BAC = serum value ÷ 1.2. Use for clinical reference.
Ethanol Blend Calculator (E10 / E85 / Fuel Mix)
Calculate final ethanol percentage when mixing E85 (85% ethanol) with regular gasoline (E10). Ideal for flex-fuel vehicles.
Chemistry deep dive: Ethanol (C₂H₅OH) essentials
📐 Calculate the formula mass of ethanol (C₂H₅OH)
Step-by-step: Atomic masses: C = 12.01, H = 1.008, O = 16.00.
Formula mass = (2×12.01) + (6×1.008) + 16.00 = 46.068 g/mol. Use this for molarity, mole fraction and yield calculations.
⚡ Exclusive 2026 insight: US ethanol blending & E15 year-round
Since 2026, the EPA has approved year-round E15 sales across all states. Our ethanol blend calculator helps you determine if your fuel mixture stays within OEM recommendations. For E85 flex-fuel, blend ratios directly affect octane (100+ RON) and fuel economy — calculate precisely.
Ethanol properties reference table (2026)
| Property | Value (Ethanol, 1 atm) | Notes |
|---|---|---|
| Boiling point (normal) | 78.37 °C (173.1 °F) | Ethanol boiling point calculator available on request |
| Boiling point under vacuum (50 mmHg) | ~31.5 °C | Vacuum distillation reference |
| Density (20°C) | 0.7893 g/mL | Ethanol water density calculator uses this |
| Vapor pressure (20°C) | 5.95 kPa | Used in vapor pressure of ethanol calculator |
| Freezing point of 70% ethanol solution | -52°C (-62°F) | Antifreeze applications |
Ethanol calculation checklist (US professionals)
- For dilution: Always add alcohol to water (safety). Use C1V1 = C2V2 formula.
- BAC estimation: Widmark formula with metabolism rate ~0.015%/hour. Our calculator applies elimination automatically.
- Serum ethanol to BAC: Divide serum ethanol (mg/dL) by 1.2 → whole blood g/dL.
- Ethanol yield fermentation: Theoretical yield = (sugar mass × 0.511) g ethanol.
- OSRS & brewing: Use our ethanol mix calculator litres for homebrew adjustments.
Frequently asked questions – Ethanol Calculator
Our BAC estimator uses the Widmark formula, but individual metabolism varies. Always use certified breathalyzers for legal evidence. For clinical use, serum ethanol to bac calculator provides a reference.
Yes, simply enter starting conc 95%, target 70%, volume desired. The result shows exactly how much distilled water to add — perfect for lab disinfectant prep.
46.07 g/mol. It’s critical for converting grams to moles in molarity, combustion enthalpy, and stoichiometric reactions.
Absolutely. Enter your E85 volume and regular gas (E10/E0) to compute final ethanol %. Tune Plus and Brew City Boost users often rely on this for custom maps.
Use our dilution calculator in reverse: known volumes and densities. Or measure using alcoholmeter corrected for temperature (our future tool).
Using ΔTf = Kf × m (ethanol Kf = 1.99 °C·kg/mol), freezing point depression ≈ -0.6°C from pure ethanol (-114.1°C). For precise results, use our dedicated formula.