Starlight Tools

Starlight Tools directory

Health & Fitness Tools

15 free, browser-based tools. No account required.

Free browser-based health and fitness calculators for BMI, body fat, BMR, TDEE, heart health, hydration, growth percentiles, and running pace—all private and client-side. Try our BMI Calculator, BMR Calculator, Calorie/TDEE Calculator, or Pace Calculator.

Health and fitness BMI calculator inputs for height weight and category gauge

BMI Calculator

Calculate your Body Mass Index (BMI) using imperial or metric units. v1.0

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Health and fitness BMI vs body fat percentage calculator comparing US Navy and Deurenberg estimates

BMI vs Body Fat %

Compare BMI with body fat % using US Navy & Deurenberg methods — metric/imperial, friendly categories, mini chart. v1.0

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Health and fitness BMR calculator showing basal metabolic rate formulas and TDEE multipliers

BMR Calculator

Estimate Basal Metabolic Rate via Mifflin–St Jeor, Harris–Benedict, Katch–McArdle & Schofield — with TDEE multipliers. v1.0

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Health and fitness Calorie TDEE calculator with maintenance and goal calories using activity multipliers

Calorie (TDEE) Calculator

Estimate daily maintenance & goal calories with activity multipliers — 100% client-side. v1.0

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Health and fitness Calories burned calculator inputs for activity type weight and duration using MET values

Calories Burned by Activity

Pick an activity, enter weight and time, and see kcal burned using MET values. Private, client-side. v1.0.0

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Health and fitness Ideal weight calculator showing Broca Devine Hamwi and Robinson results with frame size

Ideal Weight Calculator

Estimate ideal body weight with Broca, Devine, Hamwi, and Robinson formulas. Metric & imperial, frame-size tweak. v1.0.0

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Health and fitness Blood pressure zone calculator classifying systolic and diastolic readings with ACC AHA and NICE thresholds

Blood Pressure Zone Calculator

Classify clinic, home, or ambulatory readings using ACC/AHA & NICE thresholds with a calm zone bar. v1.0.0

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Health and fitness Blood sugar HbA1c converter between NGSP IFCC and estimated average glucose mg dL mmol L

Blood Sugar / HbA1c Converter

Convert HbA1c (NGSP % ↔ IFCC mmol/mol) and estimated average glucose (eAG) in mg/dL ↔ mmol/L. v1.0.0

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Health and fitness Cholesterol ratio and risk calculator for total HDL LDL non HDL and AIP

Cholesterol Ratio & Risk Calculator

Compute Total/HDL, LDL/HDL, Non-HDL, and AIP with a gentle, private-by-design interface. v1.0.0

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Health and fitness Child growth percentiles tool showing CDC and WHO curves for weight length height BMI head circumference

Child Growth Percentiles (CDC & WHO)

Calm, private percentiles for weight, length/height, BMI and head circumference. WHO 0–5y and CDC 2–20y. v1.0.0

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Health and fitness Water intake calculator estimating daily hydration needs from weight exercise climate and altitude

Water Intake Calculator

Estimate daily hydration needs from weight, exercise, climate & altitude — plus pregnancy/lactation options. v1.0.0

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Heart beats counter showing lifetime beats and animal comparisons

Heart Beats Counter

Estimate daily, yearly, and lifetime heartbeats, see beats saved by lower bpm, and compare to animals with wildly different heart rates. v1.0

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Health and fitness One rep max calculator with weight and reps inputs using Epley Brzycki and Lombardi formulas

1RM Calculator

Estimate your one-repetition max using Epley, Brzycki, and Lombardi formulas. v1.0

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Health and fitness Race split planner showing even and negative split tables for 5K 10K half marathon and marathon

Race Split Planner

Plan even or negative splits for 5K/10K/Half/Marathon with per-km/mi tables and CSV export — 100% client-side. v1.0

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Health and fitness Pace speed time calculator converting between pace speed distance and time for running

Pace / Speed / Time Calculator

Enter any two (pace, speed, time, or distance) and compute the third. Km/mi aware, instant conversions. v1.0

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About These Health & Fitness Tools

These calculators run entirely in your browser—no uploads or sign-ups—covering body composition, metabolism, heart health, hydration, growth charts, and training metrics.

Popular picks include the BMI Calculator, BMR Calculator, Calorie/TDEE Calculator, Cholesterol Ratio Calculator, and Pace Calculator. Use them free anytime.