Free Online Calculators
693+ calculators for finance, health, math, engineering, and more. No signup required.
Browse by Category
Find the perfect calculator for your needs
Conversion
83 calculators
Health & Fitness
56 calculators
Math
54 calculators
Finance
36 calculators
Fitness
23 calculators
Coffee Roasting
22 calculators
Crochet
21 calculators
Homesteading
21 calculators
Homebrewing
21 calculators
Beekeeping
21 calculators
Composting
21 calculators
RV/Van Life
21 calculators
Knitting
20 calculators
Aquarium
20 calculators
Automobile
17 calculators
Business
16 calculators
Home & Garden
15 calculators
Utilities
13 calculators
Physics
11 calculators
Leathercraft
11 calculators
Date & Time
10 calculators
Lifestyle
7 calculators
Chemistry
7 calculators
Engineering
5 calculators
Education
5 calculators
Entertainment
4 calculators
Geometry
1 calculators
Popular Calculators
Most-used tools across all categories
MAP Calculator - Mean Arterial Pressure
Calculate Mean Arterial Pressure (MAP) from systolic and diastolic blood pressure readings. Professional medical tool for cardiovascular assessment, organ perfusion evaluation, and clinical decision-making.
Health →BSA Calculator
Calculate Body Surface Area (BSA) using validated medical formulas including Du Bois, Mosteller, and Haycock. Essential for chemotherapy dosing, cardiac assessments, and clinical calculations with detailed medical reference content.
Health →Weight Gain Calculator
Calculate your personalized weight gain plan with calorie targets, macro breakdown, and healthy timeline recommendations for sustainable muscle building.
Health →BMI Calculator for Men
Professional BMI calculator designed specifically for men's unique physiological characteristics. Accounts for male muscle mass distribution, fat storage patterns, and age-related body composition changes with personalized fitness recommendations.
Health →Trigonometry Calculator
Calculate trigonometric functions including sine, cosine, tangent, and their inverses. Perfect for students, engineers, and professionals with detailed explanations and formulas.
Math →BMI Calculator for Women
Professional BMI calculator designed specifically for women's health needs with female-specific health considerations, reproductive health guidance, and personalized recommendations based on female physiology.
Health →Wheel Size Calculator
Calculate the impact of changing wheel sizes on tire specifications, speedometer accuracy, and vehicle performance. Professional tool for wheel upgrades and plus sizing projects with comprehensive analysis.
Automobile →Calorie Deficit Calculator for Women
Calculate optimal calorie deficits specifically designed for female physiology. Account for hormonal fluctuations, menstrual cycles, and women's unique metabolic characteristics for safe, sustainable weight loss.
Health →Recently Added
Fresh calculators just added to our collection
Coffee Airflow/Fan Speed Calculator
Calculate phase-specific roast airflow and fan-speed recommendations from current ROR and roaster class.
Coffee Batch Size Scaling Calculator
Scale coffee roast profile checkpoints and charge-temperature estimates between different roast batch sizes.
Coffee Bean Density Calculator
Calculate green coffee density from measured sample mass and volume for roast setup and lot comparison.
Coffee Bean Moisture Content Calculator
Calculate green coffee moisture percentage and roast setup adjustment recommendations from sample mass data.
Coffee Blend Ratio Calculator
Convert coffee blend percentages into exact component weights and weighted roast-index estimates.
Coffee Charge Temperature Calculator
Estimate roast charge temperature using roaster class, batch load, ambient conditions, and green bean temperature.
Why Complete Calculators?
Accurate Formulas
Each calculator uses verified formulas from authoritative sources. Check our sources section on each tool.
Private & Secure
Calculations happen in your browser. We don't store your data or require any login.
Works Everywhere
Mobile-friendly design. Use on your phone, tablet, or desktop - no app download needed.
Frequently Asked Questions
Are these calculators really free?
Yes, all 693+ calculators are completely free to use. No subscription, no hidden fees, no signup required. We support the site through minimal, non-intrusive advertising.
How accurate are the calculations?
We use industry-standard formulas and cite our sources on each calculator page. For professional or legal decisions, we recommend consulting with a qualified professional.
Is my data private?
All calculations are performed locally in your browser. Your input data is never sent to our servers or stored anywhere. Close the page and your data is gone.
Can I suggest a new calculator?
We're always adding new calculators based on user needs. Contact us with your suggestion and we'll consider adding it to our collection.
Start Calculating
Find the tool you need from our collection of 693+ free calculators.