Calculator Tools — Everyday Maths, Money and Dates Free
Calculator tools answer everyday money, date and percentage questions with deterministic arithmetic, showing the formula and the rounding rule so a result can be checked by hand.
All Calculators tools
- Age Calculator
Work out exact age in years, months, days, and total days lived.
- Break-Even Calculator
Find the units and revenue needed to cover fixed costs at a given price and unit cost.
- Compound Interest Calculator
Grow savings projections with annual, quarterly, or monthly compounding.
- Date Difference Calculator
Count days, weeks, and whole months between two calendar dates.
- Discount Calculator
Work out sale savings, final price, and totals for any discount percent.
- Freelance Rate Calculator
Estimate the floor hourly rate that covers a take-home target, expenses, and a tax reserve.
- GPA Calculator
Compute a weighted GPA from course grades and credits on any scale.
- Hijri and Gregorian Date Converter
Accurate Hijri converter to convert dates between the Islamic Hijri calendar and Gregorian calendar with weekdays and age calculation.
- Hourly Rate Calculator
Turn a target income, annual expenses, and working assumptions into a minimum hourly rate.
- Loan Amortization Schedule
Calculate full loan amortization schedules, monthly interest versus principal breakdowns, and early payoff savings with exportable tables.
- Loan Payment Calculator
Estimate fixed monthly loan payments, totals, and interest cost.
- Markup Calculator
Price a product from a target markup, or read markup and margin from cost and price.
- Number to Words Converter
Convert any number to words and currency amounts into written English and Arabic text for checks, receipts, and invoices.
- Percentage Calculator
Work out X percent of Y, ratios, and percent change precisely.
- ROI Calculator
Work out net gain and return on investment from cost, final value, and side amounts.
- Salary & End of Service Calculator
Free salary calculator to calculate net monthly income after social insurance deductions and labor law end-of-service gratuity.
- Sales Tax Calculator
Add tax to a net price or extract it from a gross total, to the cent.
- Timezone Converter
Compare one wall-clock time across IANA timezones, with daylight-saving rules applied.
- Tip Calculator
Split restaurant bills fairly: tip, total, and per-person shares.
- Unit Converter
Convert length, mass, temperature, volume, area, speed, data size, and time units exactly.
- VAT Calculator
Add VAT to a net amount or strip it from a gross figure, to the cent.
- Zakat Calculator
Calculate your annual Zakat on money, gold, silver, investments, and business trade goods.
- Bandwidth & Storage Calculator
Calculate file transfer times, hosting bandwidth usage, and cloud egress costs with our free bandwidth storage calculator in your browser.
- BMI & BMR Calculator
Calculate your Body Mass Index, BMR metabolic rate, and daily TDEE calorie targets with our free bmi bmr calculator. View ideal weights and macros.
- Mortgage Calculator
Calculate monthly mortgage payments, interest rates, property taxes, and complete amortization schedules with our free in-browser mortgage calculator.
- Auto Loan Calculator
Calculate monthly car payments, trade-ins, sales tax, fees, and amortization schedule.
- Savings Goal Calculator
Calculate monthly deposits, timeline, and compound interest needed to reach any target savings goal.
- 50/30/20 Budget Calculator
Divide your take-home pay into 50% needs, 30% wants, and 20% savings with custom expense comparison.
- Fuel Cost & Trip Calculator
Calculate road trip fuel consumption, petrol expense, and carpooling costs across Metric and Imperial units.
- EV Charging Time & Cost Calculator
Calculate electric vehicle charging duration, battery charging cost, and range added across Level 1, Level 2, and DC fast chargers.
Numbers drive household and business decisions, yet the useful sums are seldom the ones a phone calculator makes easy. How many days remain before a deadline, whether a discount truly saves money, what a loan costs after interest, how savings compound across decades, or which price preserves a healthy margin: these need a formula, not a guess. This section collects focused calculators that each answer one question completely. You supply the figures; the page shows the working, the rounding rule and any assumption it made, so the outcome can be verified on paper. Freelancers price an hour of labour, shop owners test markup against profit, diners split a bill, and students convert grades. Nothing is estimated behind the scenes and no figure is quietly adjusted to look tidier. Because all arithmetic runs locally, confidential salaries, quotations and forecasts stay on your own machine. Enter fresh values, compare scenarios freely, and check the reasoning without creating an account.
Formats and limits are described per tool; each tool page states the ones that tool actually accepts and enforces.
Sizing up a money question before you commit
Money questions usually begin as a vague worry: is this discount worth it, will the loan fit, does the business actually profit. The habit that works is to answer them in order. work out the real price after the discount first, then estimate the monthly repayment if credit is involved. When savings or investments enter the picture, project the balance forward over the term rather than assuming a flat rate, and finish by check the percentage change between the two figures so the comparison stays honest.
The classic errors are mixing gross with net, forgetting that tax sits on top of a discounted price, and comparing a monthly figure against an annual one. People also treat an estimate as a promise, though a break-even point shifts the moment a fixed cost changes. Rounding too early is another quiet trap, because small differences multiply across a long term. Write each assumption down, keep the units consistent, and re-run the arithmetic after any change instead of trusting an old result.
Match the tool to the shape of the problem. Single-value questions want a percentage or discount page, time-based growth wants compound interest, repayments want the loan calculator, pricing decisions want margin and mark-up, and break-even belongs whenever volume decides viability. Ages and dates have their own dedicated counters.
Two habits repay the effort. Convert every duration into matching units first, so a weekly figure lines up with a monthly one, and label each assumption beside the sum it belongs to. When comparing offers, push identical inputs through each calculator rather than trusting a headline rate that hides fees. For a household budget, begin with net income, list fixed commitments, and only then weigh discretionary spending. Freelancers should start from a take-home target and work through expenses, taxes and billable hours instead of dividing a wish by a hoped-for schedule. Clear the page when you are done with confidential salaries.
Compare your options
| Tool | Best for | Input | Output |
|---|---|---|---|
| Age Calculator | Exact age between two dates | A birth date and a target date | Years, months, days and total days |
| Break-Even Calculator | Sales needed to cover fixed costs | Price, unit cost and fixed costs | Break-even units and revenue |
| Compound Interest Calculator | Projecting savings that grow over time | Principal, rate, frequency and term | Future value and interest earned |
When this category is NOT the answer
If the figure must become a chart, a sentence in a report or a formatted table, arithmetic alone will not finish the job. Shape the figures with the data tools before they travel into a document or dashboard.
Start here: a practical Calculators workflow
- Start with Percentage Calculator or Discount Calculator to settle the everyday arithmetic.
- Model money over time using Compound Interest, Loan Payment or the ROI Calculator.
- Check the business picture with Profit Margin, Markup Calculator or Break-Even Calculator.
Frequently asked questions about Calculators tools
Are the results rounded or exact?
Each calculator states its rounding rule and shows the formula, so you can reproduce the figure by hand; nothing is silently approximated.
Can I use these for business quotes?
Yes. Profit, markup, break-even and rate calculators are designed for quoting and planning, and every input stays on your device.
Do the calculators save my figures?
No. Values are held only while the page is open; refreshing clears them and nothing is stored on a server.
Which tool handles tax or tips?
Sales Tax Calculator adds or removes tax, VAT Calculator does the same for value-added tax, and Tip Calculator splits a bill between diners.
Categories related to Calculators
Calculators guides: which tool to pick
- Discount price or percentage change: which answer do you need?
Choose between sale pricing, general percent maths, tip splitting, and adding tax to a displayed price.
- VAT or sales tax: add it or extract it?
Pick the consumption-tax calculator by direction: net to gross, gross to net, or a discount applied before tax.
- Markup or margin: which number do you quote?
Understand why the same cost and price produce two different percentages, and which one belongs in a quote.
- Loan payment or compound growth: which calculator?
Choose between modelling money you repay, money that grows, and the return on an investment you already made.