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For adults aged 18 and over, a BMI between 18.5 and 24.9 is considered healthy. A BMI below 18.5 is underweight, 25–29.9 is overweight, and 30 or above falls into the obese category. BMI is a screening tool — it does not account for muscle mass, bone density, or fat distribution. Use our BMI Calculator for an instant result.

A safe and sustainable calorie deficit for weight loss is typically 500–750 calories below your Total Daily Energy Expenditure (TDEE). For most adults, this results in about 0.5–1 kg (1–2 lbs) of loss per week without extreme restriction. Use our Calorie Intake Calculator to get a personalized number.

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to maintain vital functions — breathing, circulation, and cell repair. Knowing your BMR helps you set realistic calorie goals and understand your metabolism. Calculate yours with our BMR Calculator.

For men, 8–19% is generally considered healthy (athletes: 6–13%), while for women it is 21–33% (athletes: 14–20%). Body fat above these ranges is associated with higher risk of metabolic conditions. Estimate yours using our Body Fat Percentage Calculator.

Online health calculators use clinically validated formulas (such as the Mifflin-St Jeor equation for BMR, or the US Navy method for body fat). They provide reliable estimates for most healthy adults. These tools are intended for general wellness guidance — always consult a qualified healthcare provider before making medical decisions.

In a standard 28-day cycle, ovulation typically occurs around day 14 — roughly 14 days before the next expected period. Cycles vary between 21 and 35 days, so the ovulation window shifts accordingly. Track your personal window using our Ovulation Calculator.

The standard method is Naegele's Rule: add 40 weeks (280 days) to the first day of your last menstrual period (LMP). Only about 5% of babies are born exactly on their due date, but the estimate is used to track pregnancy milestones. Use our Due Date Calculator for a quick result.

Intermittent fasting (IF) cycles between eating and fasting periods. Common schedules include 16:8, 18:6, and 5:2. The "best" protocol depends on your schedule and goals. Plan yours with our Intermittent Fasting Calculator.

No. All Joltx calculators run entirely in your browser. The values you enter are processed locally and are never transmitted to our servers or stored anywhere. See our Privacy Policy for full details on how we handle site analytics and cookies.