Free Online Calculator Tools — BMI, TDEE, Percentage, Age & More
Our calculator tools go beyond simple arithmetic. They solve the specific calculation problems that people search for every day: working out a healthy BMI and what it means, finding your total daily calorie needs for weight management, calculating the exact age difference for a legal document, working out percentage changes for a financial report, or splitting a restaurant bill with tip for a group.
Each calculator on CalcDash is designed to be genuinely useful rather than just technically functional. They show their work — displaying the formula used and explaining what the result means in plain language — so you understand the answer, not just read a number. Where relevant, results include context like WHO classification tables, recommended calorie targets, or tipping etiquette guides.
These tools are used by students checking assignment answers, healthcare professionals running quick screeners, individuals tracking fitness goals, shoppers working out discounts, restaurant diners splitting bills, and professionals needing quick financial calculations. All calculators are free, work on mobile, and require no signup.
All Calculator Tools (15)
Percentage Calculator
Calculate percentages, percentage change, and what percent one number is of another. Free online percentage calculator for everyday math.
Use Percentage Calculator →Age Calculator
Calculate exact age in years, months, and days from a birth date. Free online age calculator with next birthday countdown and life statistics.
Use Age Calculator →PopularTDEE Calculator
Calculate your Total Daily Energy Expenditure free online. Find your daily calorie needs based on weight, height, age, and activity level instantly.
Use TDEE Calculator →BMI Calculator
Calculate your Body Mass Index free online. Enter your height and weight to get your BMI score, category, and healthy weight range instantly.
Use BMI Calculator →Tip Calculator
Calculate tips and split bills free online. Enter your bill total, tip percentage, and number of people to instantly see tip amount and per-person cost.
Use Tip Calculator →PopularLoan Calculator
Calculate monthly loan payments, total interest, and amortisation schedule free online. Works for mortgages, car loans, and personal loans.
Use Loan Calculator →Compound Interest Calculator
Calculate compound interest growth on savings and investments free online. See how money grows over time with annual, monthly, or daily compounding.
Use Compound Interest Calculator →Date Calculator
Calculate the number of days between two dates free online. Add or subtract days from a date to find a future or past date instantly.
Use Date Calculator →Time Calculator
Add and subtract hours, minutes, and seconds online. Calculate time duration between two times. Free time calculator for scheduling and payroll.
Use Time Calculator →Salary Calculator
Convert hourly wage to annual salary and calculate take-home pay after tax free online. Works for US federal and state tax estimates.
Use Salary Calculator →Fraction Calculator
Add, subtract, multiply, and divide fractions online free. Simplify fractions and convert between fractions and decimals instantly.
Use Fraction Calculator →GPA Calculator
Calculate your GPA free online. Enter your courses, grades, and credit hours to get your semester and cumulative GPA instantly.
Use GPA Calculator →PopularScientific Calculator
Free online scientific calculator with trigonometry, logarithms, exponents, and memory functions. Evaluate complex mathematical expressions instantly.
Use Scientific Calculator →Binary Calculator
Add, subtract, multiply, and divide binary numbers online free. Shows step-by-step working and decimal equivalents for every operation. No signup needed.
Use Binary Calculator →Calorie Calculator
Calculate daily calorie needs online free using the Mifflin-St Jeor equation. Get personalized calorie goals for weight loss, maintenance, or muscle gain.
Use Calorie Calculator →Frequently Asked Questions
- Are these online calculators accurate?
- Yes. Every calculator uses the correct formula for its purpose — for example, the BMI calculator uses the WHO-standard formula and displays the official WHO classification table. Results are rounded to appropriate decimal places for practical use.
- What is the most popular calculator on CalcDash?
- The BMI Calculator and TDEE Calculator are our most-used tools, followed closely by the Percentage Calculator and Age Calculator. All four are completely free with no signup.
- How is BMI calculated?
- BMI = weight (kg) ÷ height (m)². In imperial units, BMI = 703 × weight (lbs) ÷ height (inches)². The WHO classifies results as: underweight (below 18.5), normal (18.5–24.9), overweight (25–29.9), and obese (30+).
- What formula does the TDEE calculator use?
- The Mifflin-St Jeor equation, which is widely regarded as the most accurate general-purpose BMR formula. It takes weight, height, age, and sex as inputs, then multiplies the BMR result by an activity factor between 1.2 (sedentary) and 1.9 (extremely active) to give TDEE.
- Can I use these calculators for medical decisions?
- Our calculators provide useful reference information but are not a substitute for professional medical advice. BMI, TDEE, and related metrics are screening tools — always consult a qualified healthcare provider for medical decisions about diet, weight, and health.