CalcTools — Free Online Calculators & Conversion Tools

Math Calculators

• Scientific Calculator — Full-featured scientific calculator with trigonometric functions
• Percentage Calculator — Calculate percentages, percentage change, and percentage difference
• Fraction Calculator — Add, subtract, multiply, and divide fractions
• Average Calculator — Calculate mean, median, mode, and range
• Standard Deviation Calculator — Calculate standard deviation, variance, and statistical measures

Finance Calculators

• Discount Calculator — Calculate discounts, sale prices, and savings
• Compound Interest Calculator — Calculate compound interest and investment growth
• Mortgage Calculator — Calculate monthly payments and loan amortization
• Loan Calculator — Calculate loan payments, total interest, and amortization
• Savings Calculator — Calculate future value of savings with contributions

Health Calculators

• BMI Calculator — Calculate Body Mass Index and weight category
• Calorie Calculator — Calculate daily calorie needs based on activity level
• Ideal Weight Calculator — Calculate ideal body weight based on height and frame
• Body Fat Calculator — Calculate body fat percentage using US Navy method
• BMR Calculator — Calculate Basal Metabolic Rate and daily calorie needs

Conversion Tools

• Length Converter — Convert between meters, feet, inches, miles, and more
• Weight Converter — Convert between kg, pounds, ounces, and more
• Temperature Converter — Convert between Celsius, Fahrenheit, and Kelvin
• Speed Calculator — Calculate and convert speed between different units

Date & Time

• Age Calculator — Calculate exact age from date of birth
• Date Calculator — Calculate date difference or add/subtract days
• Time Calculator — Add, subtract, and convert time units

Other Calculators

• GPA Calculator — Calculate Grade Point Average from course grades
• Margin & Markup Calculator — Calculate profit margins and markup percentages
• Simple Interest Calculator — Calculate simple interest on loans and investments
• Concrete Calculator — Calculate concrete volume for slabs, footings, and columns
• Square Footage Calculator — Calculate area for flooring, painting, and landscaping

Are these calculators free?

Yes, all calculators are completely free with no signup required.

How accurate are the calculations?

All calculators use industry-standard formulas for professional-grade accuracy.

Do you store my data?

No. All calculations are performed locally in your browser. No data is sent to any server.