Health & fitness

How to choose (21 checks)

1. Start with BMI for a simple weight/height overview.
2. For daily calories, use the calorie planner.
3. If maintenance and target calories are already known, use Calorie Deficit to pressure-test the daily gap before you lock macros.
4. If the plan is for gaining and maintenance plus target intake are already known, use Calorie Surplus to pressure-test the daily surplus before you lock macros.
5. If calories are not the question and you first need a hydration baseline for the day, use Water Intake before detailed nutrition planning.
6. If the daily water target is already fixed and the next job is timing it across the day, use Hydration Schedule after Water Intake.
7. If the remaining question is what to drink before one workout starts, use Pre-Workout Hydration Plan after the daily baseline and before the during-workout page.
8. If the question is how much fluid one training session actually cost you, use Sweat Rate after the session data is available, then loop back to Water Intake or Hydration Schedule to update the plan.
9. If session loss is already known and the missing step is what to do during the workout itself, use Workout Hydration Plan before you hand the remaining liters to recovery.
10. If the during-workout pace already looks realistic and the next question is how many bottles to start with or whether one refill point is enough, use Hydration Bottle Plan after Workout Hydration Plan.
11. If bottle count and sodium context already look believable and the remaining question is what should go into each bottle, use Electrolyte Bottle Plan between bottle logistics and recovery planning.
12. If the per-bottle sodium target already looks believable and the remaining question is how many tabs, scoops, or servings that means in the actual bottle, use Electrolyte Drink Mix after Electrolyte Bottle Plan.
13. If sweat rate already looks believable and the next question is how large sodium loss may be before you choose drink composition, use Sodium Loss Estimator before Electrolyte Needs.
14. If the session loss is already known and the next job is how to replace it over the next hours, use Rehydration Plan after Sweat Rate.
15. If the session loss is already known and you first want to judge how large that loss was relative to starting body weight, use Dehydration Percent before finalizing rehydration.
16. If session loss is already known and the open question is whether plain water is still enough or electrolytes should move up in priority, use Electrolyte Needs before you finalize the recovery drink plan.
17. If the daily intake is already fixed and the remaining job is meal-by-meal execution, use Meal Calorie Split before detailed protein or macro work.
18. If you only need a daily protein range by body weight and goal, use Protein Intake before detailed macro planning.
19. If the daily protein target is already fixed and you want meal-by-meal gram targets, use Protein Per Meal before the final macro split.
20. If daily protein, carbs, and fat are already fixed and you want a meal-by-meal execution table, use Macro Per Meal after Protein Per Meal.
21. If calories are already set and you need gram targets, use the macro calculator.
22. For a body fat estimate, use the body fat calculator.
23. For training intensity, check heart rate zones.

Note: Results are for educational use only and may not reflect medical advice.

Use the health calculators as a sequence, not as isolated pages

This topic is easiest when you split the job into two questions: what is the current baseline, and what intake or training target are you trying to set. For weight-management work, the clean path is to estimate maintenance, choose a calorie target, pressure-test the daily deficit or surplus, set a protein floor, and only then lock a full macro split. Ideal weight belongs earlier in the process as a goal-range reference, not as a daily intake calculator.

Recommended calorie-planning path

1. Use BMR & TDEE or Calorie Planner when maintenance calories or the target itself are not fixed yet.
2. Use Calorie Deficit once maintenance and target intake are already known and you want to test a cutting gap.
3. Use Calorie Surplus once maintenance and target intake are already known and you want to test a gaining surplus.
4. Use Water Intake when the missing baseline is hydration rather than calories, protein, or macros.
5. Use Hydration Schedule after daily liters are already fixed and the remaining job is distributing water across real drink windows.
6. Use Pre-Workout Hydration Plan after the daily schedule is clear when the next question is what should happen in the one to four hours before training starts.
7. Use Sweat Rate after training when you want session-specific fluid loss from weigh-in and drink data instead of a generic daily baseline.
8. Use Dehydration Percent after session loss is known when the next question is how large that loss was relative to starting body weight.
9. Use Workout Hydration Plan when session loss is already known and the remaining question is the drink rhythm during the session rather than before or after it.
10. Use Hydration Bottle Plan after the during-session pace is roughly acceptable and the remaining question is bottle count, bottle size, or refill logistics.
11. Use Electrolyte Bottle Plan after bottle count and sodium context already look believable and the remaining question is how much sodium belongs in each bottle.
12. Use Electrolyte Drink Mix after the per-bottle sodium target is already believable when the remaining step is translating that target into tabs, scoops, or serving fractions.
13. Use Sodium Loss Estimator after sweat rate is already believable when the next question is the rough sodium range behind that fluid loss.
14. Use Rehydration Plan after session loss is known and you need a practical replacement schedule with larger early drinking blocks.
15. Use Electrolyte Needs after session loss or sodium context is known when the remaining question is whether recovery still looks like plain water first, mixed support, or electrolyte-priority.
16. Use Meal Calorie Split when the daily calorie target is fixed and you need a practical breakfast / lunch / dinner plan.
17. Use Protein Intake to set a body-weight-based protein checkpoint before you decide the full split.
18. Use Protein Per Meal when the daily protein number is fixed and you want practical breakfast / lunch / dinner gram targets.
19. Use Macro Calculator to lock the final daily protein, carb, and fat grams.
20. Use Macro Per Meal when the daily PFC totals are already fixed and you want a meal-by-meal execution table.

When to use another page first

• Start with BMI or Body Fat when the immediate question is baseline status rather than intake planning.
• Use Ideal Weight when you need a height-based goal range before you decide calories.
• Use Heart Rate Zones when the decision is training intensity, not nutrition planning.

Checks before you trust the output

• Keep body weight, unit system, and activity assumptions consistent across pages.
• Save one URL after the maintenance estimate and another after the final intake plan so the reasoning can be reviewed later.
• Treat each result as a planning range, not as diagnosis or treatment advice.

See also

• BMR & TDEE
• Calorie Planner
• Calorie Surplus
• Water intake
• Hydration schedule
• Pre-workout hydration plan
• Sweat Rate
• Dehydration Percent
• Workout Hydration Plan
• Hydration Bottle Plan
• Electrolyte Bottle Plan
• Sodium Loss Estimator
• Rehydration Plan
• Electrolyte Needs
• Meal Calorie Split
• Protein Per Meal
• Macro Per Meal
• Ideal Weight
• Unit conversion

Recommended (top 3)

If you are unsure where to start, these cover the most common tasks.

Calculators

Tools

Choose the health page by the decision you need to make

This hub is for picking the right health or fitness calculator before you start entering numbers. Start with the type of question: body metric, calorie planning, workout pacing, or classroom-style health screening.

Where to go first

• Body metrics: BMI, body-fat, ideal-weight, and simple screening checks
• Calories and metabolism: BMR/TDEE, calorie planning, and intake-style estimators
• Workout pacing: heart-rate zones, pace support, and practical activity checks
• Planning and life events: due-date and other timeline-oriented health pages

When to leave this hub

Move to date/time or finance topics when the question becomes scheduling, budgeting, or lifestyle planning rather than a health metric itself.

FAQ

Related hubs

• Date & time calculators
  Use these when your next step is scheduling, countdowns, or interval planning rather than health math.
• Business finance & accounting calculators
  Move here if the question shifts to pricing, budgeting, or operating decisions instead of personal metrics.
• Data visualization
  Open this hub when you need to chart or present the outputs rather than calculate them.