Life & health calculators

All life & health tools

• Ideal weight calculator – Devine, Hamwi and BMI ranges.
  Estimate ideal body weight with the Devine, Hamwi, Robinson and Miller formulas, set a custom BMI goal.
• Body Fat Percentage Calculator.
  Estimate body fat percentage with the US Navy circumference method or BMI (Deurenberg).
• Due Date Calculator (LMP, IVF, Ultrasound).
  Estimate your pregnancy due date and current gestational age from LMP, conception, IVF transfer, or ultrasound date.
• 1RM (One-Rep Max) & Training Weight Calculator.
  Estimate your 1RM from weight and reps using common formulas, then convert to training weights by %1RM or target reps.
• Aid Station Fueling Plan.
  Turn hourly fluid, sodium, drink-carb, and gel targets into aid-station actions with carry limits, refill timing.
• Calorie & Weight-loss Planner.
  Estimate your TDEE, set a calorie target to reach your goal weight by a chosen date, or see how long it may take.
• Calorie Deficit Calculator.
  Compare maintenance calories and target intake, then estimate daily calorie deficit, weekly deficit, and rough weekly.
• Calorie Surplus Calculator.
  Compare maintenance calories and target intake, then estimate daily calorie surplus, weekly surplus, and rough weekly.
• Calories Burned Calculator.
  Estimate calories burned from body weight, activity MET, and minutes.
• Carb Drink Mix Planner.
  Turn a per-bottle carb target into practical scoop or serving counts, then check rounded bottle carbs, total carbs.
• Comeback Week Schedule.
  Turn recovery and return-to-training signals into a seven-day comeback week for session length, rest days.
• Crew Handoff Fueling Plan.
  Turn crew-access timing into checkpoint-by-checkpoint handoff contents for bottles, mix, gels, and electrolyte backup.
• Dehydration Percent Calculator.
  Compare a known session-loss estimate against starting body weight and see the percentage body-mass change before you.
• Drop Bag Fueling Plan.
  Turn a believable race fueling flow into drop-bag placement by checkpoint, including reserve bottles, mix, gels, tabs.
• Electrolyte Bottle Plan.
  Turn session fluid and sodium targets into a bottle-by-bottle electrolyte plan.
• Electrolyte Drink Mix.
  Turn one bottle sodium target into tablets, scoops, or serving fractions.
• Electrolyte Needs Calculator.
  Check whether a workout context still looks like plain-water territory or if electrolyte support deserves more.
• Gel Carb Schedule.
  Turn a per-hour carb target into gel timing, serving fractions, and checkpoint-by-checkpoint carb totals.
• Health & fitness calculators — BMI, calories, body fat.
  Estimate BMI, body fat %, calories, macro targets, ideal weight, heart rate zones, and due dates.
• Heart Rate Zone Calculator.
  Find your training heart rate zones in bpm using %HRmax, Karvonen (HRR), or %LTHR.
• Hydration Bottle Plan.
  Turn one during-workout drink target into a practical bottle and refill plan.
• Hydration Schedule Calculator.
  Split one daily water target across wake-up, daytime, training, or hot-weather slots, then copy a simple hydration.
• Macro Calculator.
  Turn daily calories and macro ratios into grams of protein, carbs, and fat.
• Macro Per Meal Calculator.
  Split daily protein, carbs, and fat grams across 3 meals, 4 meals, or 3 meals plus a snack, then copy a simple.
• Meal Calorie Split Calculator.
  Split a daily calorie target across 3 meals, 4 meals, or 3 meals plus a snack, then copy the meal-by-meal kcal plan.
• Multi-Day Recovery Plan.
  Turn the finish-to-breakfast recovery story into a day 1 to day 3 plan for fluid, carbs, protein, easy movement.
• Next-Day Recovery Plan.
  Turn the remaining evening fluid loss into a next-day recovery note that covers dinner, pre-bed support, breakfast.
• Pet Age Calculator.
  Estimate dog or cat age in human years and life stage from species, age, and dog size.
• Post-Race Refuel Plan.
  Turn finish-line fluid loss and body mass into a first-30-minute, first-hour, and first-meal refuel note for drink.
• Pre-Workout Hydration Plan.
  Turn body weight, start time, and session context into a simple pre-workout hydration plan, then split mL across drink.
• Protein Intake Calculator.
  Estimate a daily protein intake range from body weight and goal, with quick g/kg guidance for general intake.
• Protein Per Meal Calculator.
  Split a daily protein target across 3 meals, 4 meals, or 3 meals plus a snack, then copy the meal-by-meal gram plan.
• Race Fueling Pack List.
  Turn race duration, bottle capacity, mix, gels, and backup margin into a simple pack list after your aid-station plan.
• Rehydration Plan Calculator.
  Turn a workout fluid-loss estimate into a simple post-workout rehydration plan, then split liters and mL.
• Return to Training Check.
  Turn recovery signals into a simple return-to-training check for easy, reduced, or delayed training after a hard.
• Running Pace, Time and Distance Calculator.
  Solve running pace, time, or distance from the other two.
• Session Fueling Plan.
  Combine fluid, sodium, carb drink, and gel targets into one session note with checkpoints, bottle counts.
• Sleep Cycle Calculator.
  Find suggested bedtimes or wake-up times using sleep cycles and a fall-asleep buffer.
• Sodium Loss Estimator.
  Estimate a rough sodium-loss range from sweat rate, session length, heat, and sweat saltiness.
• Sweat Rate Calculator.
  Estimate session fluid loss and sweat rate from pre/post workout weight, session duration, and drinks consumed.
• Training Load Rebuild.
  Plan weeks 2 to 4 after return-to-training with a weekly volume cap, long-session ceiling, and deload trigger.
• Training Ramp Plan.
  Turn return-to-training readiness into a short ramp plan for first-session duration, week-volume cap, and long-session.
• Water Intake Calculator.
  Estimate a daily water intake baseline from body weight, activity level, and climate, then review liters, mL, fl oz.
• Workout Hydration Plan Calculator.
  Turn a known session-loss estimate into simple drink checkpoints during a workout, then see how much fluid may still.

Choose the life or health page by the goal first

Use this hub when the question is about body metrics, calorie planning, training load, or everyday personal planning, but you have not picked the exact page yet.

Open these sections first

• Body metrics: start with BMI or body-fat pages when you need a screening-style estimate from measurements.
• Calories and metabolism: open BMR & TDEE or the calorie planner when the goal is daily intake, targets, or maintenance.
• Training load: open 1RM when the next question is lifting intensity, estimated max, or percentage-based training weight.
• Broader health routing: move to the Health & Fitness topic hub when the question expands beyond one metric.

Best workflow

1. Choose one health question.
2. Open one calculator that matches that question.
3. Return here only if the next step changes from measurement to planning, or from planning to training.

FAQ

Start with these pages

• Health & fitness topic hub
  Open this hub when you want the broader map across body metrics, calories, and workout planning.
• BMI calculator
  Use this for a quick body-mass screening estimate from height and weight.
• BMR & TDEE calculator
  Move here when the next question is daily calorie needs and maintenance intake.
• 1RM and training weight calculator
  Open this when the next step is lifting intensity, estimated max, or training percentages.