Everyday problems, solved in seconds.
Free, fast calculators and clear guides for everyday problems: money, dates, units, writing and passwords. No sign-up, no clutter, and your numbers stay in your browser.
Free tools you can use right now
Age Calculator
Find your exact age in years, months and days, plus total days lived and the countdown to your next birthday.
๏ผPercentage Calculator
Calculate X% of a number, find what percent one number is of another, and work out percentage increase or decrease.
๐ฆEMI & Loan Calculator
Calculate your monthly loan EMI, total interest and total payment, with a year-by-year breakdown of principal and interest.
๐Unit Converter
Convert length, weight, volume, speed and temperature units instantly, including cooking measures like cups and tablespoons.
๐Word & Character Counter
Count words, characters, sentences and paragraphs as you type, and see estimated reading and speaking time.
๐Days Between Dates Calculator
Find the number of days, weeks, months and business days between any two dates.
๐ท๏ธDiscount Calculator
Work out the sale price, how much you save and the final price with an extra discount and tax or VAT.
๐ฝ๏ธTip & Bill Splitter
Split a bill between friends and add a tip. See the tip, the total and the amount each person pays.
๐Strong Password Generator
Generate strong random passwords with the length and character types you choose. Created in your browser, never sent or stored.
Why people use SolveKit
Private by design
Every calculator runs inside your browser. The numbers and text you type are never sent to us.
Fast and simple
No sign-up, no downloads and no clutter. Open a tool, get your answer, move on with your day.
Explained clearly
Each tool comes with a plain-English guide, worked examples and tips, so you understand the result.
Latest guides
How to Count Days Between Two Dates: 3 Easy Methods (Including Business Days)
Count days between two dates by hand, in Excel or Google Sheets, or with a free calculator. Includes business days, holidays, leap years and mistakes to avoid.
November 6, 2026 ยท 16 min readHow to Calculate a Discount and the Real Sale Price (With VAT and Tax Examples)
Learn how to calculate a discount, stacked coupons and the real final price with VAT or sales tax. Simple formulas, worked examples and mistakes to avoid.
November 6, 2026 ยท 14 min readHow to Calculate a Percentage: A Step-by-Step Guide With Examples
Learn the three percentage formulas you need for everyday life, with worked examples for discounts, test scores, pay rises and more.
November 4, 2026 ยท 2 min readHow to Calculate Your Exact Age in Years, Months and Days
A simple method for working out exact age by hand, how leap years affect it, and why different countries count age differently.
November 4, 2026 ยท 2 min readHow EMI Works and 5 Ways to Reduce Your Loan Payments
Understand what is inside a loan EMI, how the term changes the total interest, and practical ways to lower what you pay. General information, not financial advice.
November 4, 2026 ยท 3 min readHow to Create a Strong Password You Can Actually Remember
Why length beats complexity, how to build a memorable passphrase, and the account-protection habits that matter most.
November 4, 2026 ยท 3 min read