Free Online Calculator Tools
Professional, accurate, and easy-to-use calculators for everyday needs. No registration required.
TDEE Calculator
Calculate your Total Daily Energy Expenditure based on your body metrics and activity level.
Salary Calculator
Calculate net pay, taxes, and deductions from your gross salary.
Scientific Calculator
Advanced calculator with trigonometry, logarithms, and more.
Fraction Calculator
Add, subtract, multiply, and divide fractions with ease.
Graphing Calculator
Plot and visualize mathematical functions interactively.
Grade Calculator
Calculate what you need on your final exam to get your desired grade.
Explore Our Calculator Features
TDEE Calculator - Your Personal Calorie Guide
Understanding your Total Daily Energy Expenditure is the foundation of any successful fitness journey. Our TDEE calculator uses the scientifically-proven Mifflin-St Jeor equation to provide accurate results.
Basal Metabolic Rate based on age, gender, height, and weight
5 activity levels from sedentary to extra active
Calories for weight loss, maintenance, or gain
Salary Calculator - Know Your True Take-Home Pay
Make informed financial decisions with our comprehensive salary calculator. See exactly how much you'll take home after federal taxes, state taxes, Social Security, Medicare, and retirement contributions.
Updated federal income tax rates
Weekly, bi-weekly, monthly, or annual
See impact of retirement contributions
Scientific Calculator - Advanced Math at Your Fingertips
A powerful scientific calculator for students, engineers, and professionals. Perform complex calculations with trigonometric functions, logarithms, exponents, and more - all in your browser.
sin, cos, tan (degrees)
log (base 10) and ln
xยฒ, xสธ, โx
ฯ, e, factorial
Fraction Calculator - Simplify Fraction Math
Whether you're a student learning fractions or need quick calculations for recipes and measurements, our fraction calculator makes it easy to add, subtract, multiply, and divide fractions.
+, โ, ร, รท fractions
Results in lowest terms
Fraction to decimal
Show as mixed fractions
Graphing Calculator - Visualize Mathematics
See math come alive with our interactive graphing calculator. Plot any mathematical function and explore how equations behave visually. Perfect for learning and analysis.
Enter any equation
Quick function buttons
Custom X and Y bounds
Clear visual reference
Grade Calculator - Plan Your Academic Success
Take control of your grades with our comprehensive grade calculator. Find out exactly what you need on your final exam, or calculate your weighted average across all assignments.
What score do you need?
Multiple assignments with weights
A, B, C, D, F conversion
Why Choose Our Calculators?
โ Accuracy Guaranteed
All formulas are verified by certified professionals and tested against industry standards.
โ Privacy First
All calculations happen in your browser. We never store your personal data.
โ Free Forever
No hidden fees, no subscriptions. All tools are completely free to use.
โ Mobile Friendly
Responsive design works perfectly on phones, tablets, and desktops.
Frequently Asked Questions
Are these calculators free to use?
Yes, all calculators on CalcTools are completely free with no registration required. We believe everyone should have access to professional calculation tools.
How accurate are the calculations?
Our calculators use industry-standard formulas. The TDEE calculator uses the Mifflin-St Jeor equation, and the salary calculator uses 2024 federal tax brackets. All calculations are performed client-side for instant results.
Is my data safe?
Absolutely. All calculations happen directly in your browser. We don't collect, store, or transmit any of your personal information or calculation data.
Can I use these calculators on my phone?
Yes! All our calculators are fully responsive and work great on smartphones, tablets, and desktop computers.