How-To Guides
Step-by-step guides that teach you how to perform calculations manually.
Biological Age Estimator: A Step-by-Step Guide
Estimate biological age from lifestyle
Read guideHow to Calculate Growth Velocity: Step-by-Step Guide
Calculate height growth rate in cm/year
Read guideHow to Calculate Body Roundness Index (BRI): Step-by-Step Guide
Calculate BRI manually
Read guideHow to Calculate BAC & Alcohol Recovery: Step-by-Step Guide
Estimate your Blood Alcohol Concentration (BAC) and time to sober up manually. Learn the formulas, see a worked example, and avoid common pitfalls.
Read guideHow to Calculate Detoxification Timelines Manually: Caffeine, Alcohol, and Nicotine
Learn to manually estimate clearance times for caffeine, alcohol, and nicotine from your body using half-life and elimination rate formulas. Includes examples and pitfalls.
Read guideHow to Manually Calculate Optimal Supplement Timing Around Workouts: A Step-by-Step Guide
Learn to manually calculate optimal supplement timing for pre-workout, intra-workout, and post-workout. Understand the formulas, see a worked example, and avoid common pitfalls.
Read guideHow to Calculate Minute Ventilation and Alveolar Ventilation: Step-by-Step Guide
Learn to manually calculate minute ventilation and alveolar ventilation using tidal volume, breathing rate, and anatomical dead space. Understand formulas and common pitfalls.
Read guideHow to Calculate Electrolyte Balance: Step-by-Step Guide
Learn to manually calculate sodium, potassium, and fluid loss from sweating. Understand the formulas, see a worked example, and ensure proper rehydration for performance.
Read guideHow to Calculate Sweat Rate: Step-by-Step Guide
Learn to manually calculate your sweat rate from exercise weight loss, fluid intake, and duration. Understand the formula, a worked example, and common pitfalls.
Read guideHow to Calculate Recovery Heart Rate: Step-by-Step Guide
Learn to manually calculate your Recovery Heart Rate (RHR) as a fitness indicator. Understand the formula, interpret results, and identify common pitfalls for better cardiovascular health.
Read guideHow to Calculate Keto Macros: Step-by-Step Guide
Learn to manually calculate your ketogenic diet macros for fat, protein, and carbs. Understand the formulas, see a worked example, and avoid common pitfalls.
Read guideHow to Calculate the Thermic Effect of Food (TEF): Step-by-Step Guide
Learn to manually calculate the Thermic Effect of Food (TEF), the calories burned digesting food, using a simple formula and macronutrient data.
Read guideHow to Calculate Your Daily Hydration Needs: Step-by-Step Guide
Learn to manually calculate your optimal daily water intake based on body weight and activity level. Understand the formula, see examples, and avoid common pitfalls.
Read guideHow to Calculate Body Fat % (Navy Method): Step-by-Step Guide
Calculate your Body Fat % using the US Navy Method. Learn the formulas for men & women, step-by-step manual calculation, and common pitfalls.
Read guideHow to Calculate Your Chronotype: Step-by-Step Guide
Manually calculate your sleep chronotype (morning lark, night owl, intermediate) using your mid-sleep point. Understand the formula and interpret results.
Read guideHow to Calculate Sleep Debt: Step-by-Step Guide
Learn to manually calculate your accumulated sleep debt. Understand the formula, follow a worked example, and avoid common pitfalls.
Read guideHow to Calculate Intermittent Fasting Windows: Step-by-Step Guide
Learn to manually calculate your intermittent fasting and eating windows. Understand the formula, worked examples, and common pitfalls for effective planning.
Read guideHow to Calculate NEAT Calories: Step-by-Step Guide
Learn to manually calculate your Non-Exercise Activity Thermogenesis (NEAT) calories and Total Daily Energy Expenditure (TDEE) with our step-by-step guide, formulas, and examples.
Read guideHow to Calculate Creatinine Clearance: Step-by-Step Guide
Calculate creatinine clearance manually using the Cockcroft-Gault equation. Understand the formula, worked examples, and common pitfalls.
Read guideHow to Calculate IV Drip Rate: Step-by-Step Guide
Learn to manually calculate IV drip rates in drops per minute. Understand the formula, units, and common pitfalls for accurate intravenous fluid administration.
Read guideHow to Calculate Medication Dosage: Step-by-Step Guide
Learn to manually calculate veterinary medication dosages based on weight. Master the formula, avoid common errors, and ensure accurate animal care.
Read guideHow to Calculate Child Growth Percentile: Step-by-Step Guide
Learn to manually calculate child growth percentiles using WHO charts for height and weight. Understand the process, interpret results, and avoid common errors.
Read guideHow to Calculate eGFR (CKD-EPI Formula): Step-by-Step Guide
Learn to manually calculate estimated Glomerular Filtration Rate (eGFR) using the CKD-EPI 2009 formula. Understand inputs, formula variations, and common pitfalls.
Read guideHow to Calculate FEV1 Spirometry Results: Step-by-Step Guide
Learn to manually calculate FEV1/FVC ratio, percent predicted FEV1, and GOLD classification from spirometry results. Understand the formulas.
Read guideHow to Calculate Your Wedding Costs: Step-by-Step Guide
Learn to manually estimate your wedding budget, covering guest count, venue, catering, and other key expenses. Understand the formula and common pitfalls.
Read guideHow to Calculate Heart Rate Zones: A Step-by-Step Guide
Calculate 5 training zones using Karvonen method
Read guideHow to Calculate Waist-to-Hip Ratio: Step-by-Step Guide
Calculate WHR manually for health risk assessment
Read guideDiabetes Risk Calculator: A Step-by-Step Guide
Calculate your diabetes risk manually
Read guideHow to Calculate Blood Pressure Metrics: A Step-by-Step Guide
Calculate MAP and pulse pressure manually
Read guideMoving Cost Estimator: A Step-by-Step Guide
Calculate moving costs manually
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