The complete index
All tools
Every free tool on Smart Tool, grouped by category. Pick one to start — no sign-up required.
Calculators
Percentage Calculator
Solve every common percentage question: of, change, increase and decrease.
Age Calculator
Find your exact age in years, months and days, plus total days lived.
Date Difference Calculator
Count the days, weeks and months between two dates.
Date Calculator
Add or subtract days, weeks, months or years from any date.
Time Calculator
Add and subtract hours, minutes and seconds.
Average Calculator
Calculate the mean, median, mode, sum and count of a list of numbers.
Ratio Calculator
Simplify ratios and solve for a missing value in a proportion.
Fraction Calculator
Add, subtract, multiply and divide fractions with simplified results.
Random Number Generator
Generate random numbers within a range, with optional uniqueness.
Number Sequence Generator
Create arithmetic or geometric number sequences.
Scientific Calculator
A full scientific calculator with trigonometry, logarithms and more.
Unit Converters
Length Converter
Convert between meters, feet, miles, kilometers, inches and more.
Weight & Mass Converter
Convert kilograms, pounds, ounces, grams, tonnes and more.
Temperature Converter
Convert Celsius, Fahrenheit and Kelvin.
Area Converter
Convert square meters, acres, hectares, square feet and more.
Volume Converter
Convert liters, gallons, milliliters, cups and more.
Speed Converter
Convert km/h, mph, m/s, knots and more.
Time Converter
Convert seconds, minutes, hours, days, weeks and years.
Data Storage Converter
Convert bytes, KB, MB, GB, TB and bits.
Energy Converter
Convert joules, calories, kWh, BTU and more.
Pressure Converter
Convert pascals, bar, psi, atm and more.
Power Converter
Convert watts, kilowatts, horsepower and more.
Frequency Converter
Convert hertz, kilohertz, megahertz and gigahertz.
Fuel Economy Converter
Convert MPG, km/l and L/100km.
Finance Calculators
EMI Calculator
Calculate your monthly loan EMI, total interest and total repayment with a full amortization schedule.
SIP Calculator
Estimate the future value of your monthly SIP investments and see how your wealth can grow over time.
Compound Interest Calculator
See how your savings grow with compound interest across different compounding frequencies.
Simple Interest Calculator
Quickly calculate simple interest and the total amount payable on a principal.
Loan Calculator
Work out monthly payments, total interest and total cost for any loan.
Mortgage Calculator
Estimate monthly mortgage payments including principal and interest.
GST Calculator
Add or remove GST from a price with inclusive and exclusive modes.
Discount Calculator
Find the sale price and how much you save after a percentage discount.
Profit Margin Calculator
Calculate gross profit and profit margin from cost and selling price.
ROI Calculator
Measure return on investment as a percentage and net gain.
CAGR Calculator
Compute the compound annual growth rate of an investment.
Inflation Calculator
See how inflation changes the future value and buying power of money.
Salary Calculator
Convert between annual, monthly, weekly, daily and hourly pay.
Income Tax Calculator
Estimate income tax using a configurable progressive slab framework.
Student Tools
CGPA Calculator
Calculate your CGPA from semester GPAs and convert it to a percentage.
GPA Calculator
Compute your GPA from course grades and credit hours.
Grade Calculator
Convert a score into a letter grade and see the grade needed to pass.
Marks Percentage Calculator
Calculate your exam percentage from marks obtained and total marks.
Attendance Calculator
Track your attendance percentage and how many classes you can miss.
Study Time Calculator
Plan daily study hours needed to cover your syllabus before an exam.
Exam Countdown
Count down the days, hours and minutes to your exam.
Weighted Grade Calculator
Calculate your overall grade when assignments carry different weights.
Date & Time Tools
World Clock
See the current time across major cities and time zones.
Time Zone Converter
Convert a specific time from one time zone to another.
Business Days Calculator
Count working days between two dates, excluding weekends.
Countdown Timer
A simple, accurate countdown timer with alerts.
Stopwatch
A precise stopwatch with lap times.
Pomodoro Timer
Boost focus with the Pomodoro technique of work and break intervals.
Health & Fitness
Business Tools
Invoice Generator
Create and print professional invoices — no account, fully in-browser.
Markup Calculator
Calculate selling price and markup percentage from cost.
Margin Calculator
Calculate gross margin percentage and profit.
Break-even Calculator
Find how many units you must sell to cover costs.
Commission Calculator
Calculate sales commission and total earnings.
Hourly Rate Calculator
Work out an hourly rate from a desired annual income.