All Calculators
Every calculator on HealthCalcNow, grouped by category. Each one shows its formula source, a confidence level, and a full methodology — free, private, and no sign-up.
Build, measure & improve
Fitness & Body
B
BMI Calculator
Find your Body Mass Index and see what it means for your health — using the WHO formula, with India-specific cutoffs applied automatically based on your region.
B
Body Fat Calculator
Estimate your body fat percentage from a few tape measurements using the U.
F
FFMI Calculator
Calculate your Fat-Free Mass Index (FFMI) — a 'muscularity BMI' that expresses your lean mass relative to your height.
H
Healthy Weight Range Calculator
Find the healthy weight range for your height, based on the WHO's healthy BMI band — with India-specific (Asian) cutoffs applied automatically by region.
H
Heart Rate Zones Calculator
Find your maximum heart rate and five training zones from your age, using the Tanaka formula — so you can train at the right intensity.
I
Ideal Weight Calculator
Estimate your ideal body weight from your height and sex using the Devine formula — the clinical heuristic long used for medication dosing.
L
Lean Body Mass Calculator
Estimate your lean body mass — everything that isn't fat — from your height, weight, and sex using the Boer formula.
O
One-Rep Max Calculator
Estimate your one-rep max (1RM) from a set you've done — the most weight you could lift once — using the Epley and Brzycki formulas.
P
Pace Calculator
Work out your running or walking pace and speed from a distance and time — in minutes per kilometre or per mile.
S
Steps to Calories Calculator
Estimate the calories you burned from your step count and body weight — a rough figure, useful for comparing days and tracking trends.
W
Waist-to-Height Ratio Calculator
Check your waist-to-height ratio — a simple, evidence-based screen for central body fat.
Food, calories & nutrients
Nutrition
B
BMR Calculator
Calculate your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest — using the Mifflin-St Jeor equation.
C
Calories Burned Calculator
Estimate the calories you burn during exercise from your weight, the activity, and how long you did it — using MET values from the Compendium of Physical Activities.
D
Daily Fiber Intake Calculator
Find your recommended daily fiber intake based on your sex and age, using the Institute of Medicine's Adequate Intake values.
D
Daily Sugar Intake Calculator
See the recommended daily limit for added sugars based on your sex, using the American Heart Association's guidance (and the WHO's under-10%-of-energy advice).
M
Macro Split Calculator
Split a daily calorie target into grams of protein, carbs, and fat using a preset ratio — a starting point you can adjust to your goals.
P
Protein Intake Calculator
Find your recommended daily protein range based on your body weight and activity level, from the RDA baseline up to athlete-level intake.
T
TDEE Calculator
Estimate your Total Daily Energy Expenditure — the calories you burn per day — using the Mifflin-St Jeor equation, then see targets for losing, maintaining, or gaining weight.
W
Water Intake Calculator
Get a rough daily water target from your body weight — with an honest note that hydration needs vary widely and thirst is a good guide.
For you and your baby
Pregnancy
O
Ovulation Calculator
Estimate your fertile window and likely ovulation date from your last period and cycle length.
P
Pregnancy Due Date Calculator
Estimate your due date from the first day of your last menstrual period using Naegele's Rule (LMP + 280 days).
P
Pregnancy Week Calculator
Track how many weeks pregnant you are, your trimester, and how long until your due date — counted from your last menstrual period.
P
Pregnancy Weight Gain Calculator
See the recommended total weight gain for a single pregnancy based on your pre-pregnancy BMI, using the Institute of Medicine guidelines.
Everyday essentials