Free Calculators Online

Last updated: April 2026

Free online calculators for BMI, percentages, grades, calories, and everyday math.

Our free online calculators cover everyday math and health-related calculations: BMI and body fat, calorie and macro needs, percentage and tip math, age calculations, grades, and GPA. For mortgage, loan, and retirement math, see our dedicated Finance Calculators category. Every tool runs entirely in your browser with no signup and no usage limits.

Percentage Calculator

Calculate percentages instantly: find X% of Y, percentage change, or what percent X is of Y. Free online percentage calculator - no signup required.

BMI Calculator

Calculate your Body Mass Index (BMI) instantly. Supports metric and imperial units. Free BMI calculator with health category ranges.

Age Calculator

Calculate your exact age in years, months, and days. Find total days lived, weeks, and days until next birthday. Free online age calculator.

Tip Calculator

Calculate tips and split bills instantly. Choose preset or custom tip percentages. Free tip calculator with per-person breakdown.

Calorie Calculator

Calculate your daily calorie needs based on age, gender, weight, height, and activity level. Free TDEE and BMR calculator for weight loss, maintenance, and muscle gain.

Grade Calculator

Calculate your final grade with simple or weighted averages. Free grade calculator for students with letter grade conversion. Add unlimited assignments.

GPA Calculator

Calculate your college GPA on a 4.0 scale. Free GPA calculator with letter grades, credit hours, and quality points. Add unlimited courses instantly.

Macro Calculator

Calculate your daily protein, carb, and fat targets based on your body stats, activity level, and fitness goal. Includes keto, paleo, IIFYM presets and meal-by-meal breakdown.

Body Fat Calculator

Estimate your body fat percentage using 5 methods: US Navy, Jackson-Pollock 3-site, Jackson-Pollock 7-site, BIA, and BMI-based. Compare all results side by side with health range classifications.

Frequently Asked Questions

Are these calculators free to use?

Yes, all calculators on FreeToolPark are completely free with no signup, no subscription, and no usage limits. Every calculation runs in your browser.

How accurate are the calculator results?

Our calculators use standard formulas used by health professionals, educators, and mathematicians. Results are accurate for informational and planning purposes.

Do the calculators work on mobile?

Yes, all calculators are fully responsive and work on iPhone, Android, tablets, and desktop browsers without any app installation.