CalcKitFree Online Calculators
30 fast, private calculators for health, money, productivity and everyday maths — no sign-up, works on any device.
🔥 Most Popular
The calculators people search for most
⚖️ BMI Calculator
2🎂 Age Calculator
3🔥 Calorie Calculator
4🏦 EMI / Loan Calculator
5🏠 Mortgage Calculator
6💵 Tip Calculator
7🤰 Pregnancy Due Date Calculator
8％ Percentage Calculator
9🔬 Scientific Calculator
10📈 Compound Interest Calculator
11💱 Currency Converter
12📏 Unit Converter
13💼 Salary / Tax Calculator
14📅 Date Difference Calculator
15🧬 Body Fat Calculator
16⚡ BMR Calculator
17💧 Water Intake Calculator
18😴 Sleep Calculator
19💳 Debt Payoff Calculator
20🏖️ Retirement Calculator
21🏘️ Rent vs Buy Calculator
22🔁 Refinance Calculator
23✍️ Word Counter
24🎓 GPA Calculator
25🔑 Password Generator
26⬛ QR Code Generator
27🌍 Time Zone Meeting Planner
28🍅 Pomodoro Timer
29🧾 Invoice Generator
30⏱️ Hourly Rate Calculator
Health Calculators
7 free tools
BMI Calculator
Calculate your Body Mass Index instantly and see if your weight is healthy.
Calorie Calculator
Find your daily calorie needs for weight loss, maintenance or gain.
Pregnancy Due Date Calculator
Estimate your due date, current week and trimester from your LMP.
Body Fat Calculator
Estimate your body fat percentage with the US Navy method.
BMR Calculator
Find your Basal Metabolic Rate and daily calorie burn (TDEE).
Water Intake Calculator
How much water should you drink daily? Find out in seconds.
Sleep Calculator
Find the best bedtime or wake-up time based on sleep cycles.
Finance Calculators
9 free tools
EMI / Loan Calculator
Calculate monthly loan EMI, total interest and total payable amount.
Mortgage Calculator
Estimate monthly mortgage payments, total interest and loan cost.
Compound Interest Calculator
See how your savings grow with compound interest over time.
Currency Converter
Convert between 20 world currencies with live exchange rates.
Salary / Tax Calculator
Estimate take-home pay after tax in USA, UK, Pakistan, India & Qatar.
Debt Payoff Calculator
See when you'll be debt-free and how much interest you'll pay.
Retirement Calculator
Project your retirement nest egg from monthly savings.
Rent vs Buy Calculator
Should you rent or buy? Compare the true costs side by side.
Refinance Calculator
See if refinancing saves you money and when you break even.
Everyday Calculators
5 free tools
Age Calculator
Find your exact age in years, months, days — plus total days alive.
Tip Calculator
Split the bill and calculate the perfect tip in seconds.
Percentage Calculator
Solve any percentage problem: X% of Y, percent change and more.
Unit Converter
Convert length, weight, temperature, volume, area and speed.
Date Difference Calculator
Count days between two dates or add days to any date.
Math Calculators
1 free tools
Productivity Calculators
6 free tools
Word Counter
Count words, characters, sentences and reading time instantly.
GPA Calculator
Calculate your GPA from courses, credits and grades.
Password Generator
Generate strong, random, secure passwords in one click.
QR Code Generator
Turn any text or URL into a scannable QR code instantly.
Time Zone Meeting Planner
Pick a time in your zone, see it instantly in 8 world zones.
Pomodoro Timer
A simple 25-minute focus timer with short and long breaks.
Why use CalcKit?
Private by design. Every calculation runs entirely in your browser with JavaScript — your numbers are never sent to a server, stored, or tracked. What you calculate stays on your device.
Fast on any device. No frameworks, no heavy libraries, no accounts. Pages load in a fraction of a second even on slow mobile connections, and every calculator is designed mobile-first.
Built for real questions. From "what's my BMI?" to "can I afford this mortgage?", each tool pairs an instant calculator with a plain-English guide and answers to common questions — so you understand the result, not just the number.