The full toolbox

All calculators

Every tool is free, works instantly in your browser, and never stores your data. Each calculator includes the formula it uses and a plain-English explanation of the result.

CalcOrchard is a growing library of 62 free calculators covering personal finance, UK and US tax, health, general maths, and small everyday questions. We built the site because most calculator websites we found were either bloated with pop-ups and paywalls, or so bare that you had no way to check what the result actually meant. Every tool here is deliberately simple, deliberately fast, and comes with a short explainer so you learn while you calculate.

What makes a good calculator

Three things, in order of importance. First, it uses the right formula for the question — the standard textbook or regulator equation, not an approximation somebody invented. Second, it shows its work so you can trust the answer and reproduce it if you need to. Third, it respects your privacy: your inputs stay in your browser and are never sent to a server.

Every tool on CalcOrchard follows those three rules. UK tax calculators use HMRC-published rates and thresholds. US tax calculators use IRS-published rates. Finance formulas (compound interest, present value, amortisation, dividend band walks) come straight from published references. Each new calculator is spot-checked against at least two independent worked examples before it goes live. Read more on our methodology page.

How the categories break down

Finance is our largest section, with calculators for UK take-home pay, IR35 (inside vs outside), landlord Section 24 tax, stamp duty, capital gains, mortgages, loans, compound interest, retirement, 401(k), Roth vs Traditional IRA, and more.

Math covers percentages, averages (mean/median/mode/std deviation), fractions, scientific notation, and other quick arithmetic helpers.

Health includes BMI, body fat percentage, daily calorie needs, water intake, sleep cycles, and running pace.

Everyday is a grab-bag of little useful tools: age, tip, password generator, hours between two times, unit converter, word count, and more.

Finance

Loans, savings, investing and everyday money math.

Compound Interest Calculator See how savings or investments grow over time with compound interest. Add regular contributions and visualise year-by-year growth. Loan & Mortgage Payment Calculator Work out the monthly payment on any loan or mortgage, see the total interest, and explore how extra payments help you finish sooner. Savings Goal Calculator Find out how much to save each month to reach a money goal — or how long it will take if you already know your monthly amount. Mortgage Affordability Calculator Estimate the maximum home price and mortgage you can afford based on your income, debts, and down payment. Uses the standard 28/36 qualifying ratios. ROI Calculator Calculate the return on investment for any project, stock, or business venture. Get simple ROI, annualized ROI, and see whether a gain or loss is worth it. Retirement Calculator Project your retirement nest egg from current savings, monthly contributions, expected return and years remaining. See the monthly income it can fund. 401(k) Calculator Project your 401(k) balance at retirement including employer match, salary growth and contribution limits. See exactly what the match adds. Roth vs Traditional IRA Calculator Compare Roth and Traditional IRA outcomes side by side. See after-tax retirement value under each based on your current and future tax brackets. IR35 Calculator (Inside vs Outside) Compare Inside IR35 (umbrella / PAYE) vs Outside IR35 (limited company) take-home for any UK day rate. See the annual £ difference. 2024/25 rates. UK Landlord Tax Calculator (Section 24) Work out your buy-to-let tax under Section 24. See how the 20% mortgage interest credit hits profit and compare Individual vs Ltd Co ownership. UK Company Car Tax Calculator (BIK 2024/25) Work out the annual UK company car BIK tax on any EV, hybrid, petrol or diesel car. HMRC 2024/25 P11D tables plus optional fuel benefit. Umbrella Company Take-Home Calculator Work out real weekly and annual take-home from a UK umbrella contract. Includes margin, employer NI, apprenticeship levy and holiday pay. 2024/25. CIS Tax Calculator (Construction Industry Scheme) Work out the CIS deduction on a UK subcontractor invoice and estimate your Self Assessment bill. Handles 20% and 30% rates, materials, VAT and rebates. Rental Yield Calculator (Gross & Net) Work out the real return on a UK buy-to-let: gross yield, net yield after running costs, and cash-on-cash ROI after mortgage. Compare on real numbers. Inflation Calculator Find out what a dollar was worth in any year from 1913 to today. See how inflation erodes purchasing power over time using US CPI data. Hours to Salary Calculator Convert between hourly wage and annual salary. See weekly, monthly, and yearly earnings. Calculate take-home pay after tax. Auto Loan Calculator Calculate your monthly car payment including down payment, trade-in value, sales tax, and fees. See total interest and full amortisation. Rent vs Buy Calculator Compare the true cost of renting versus buying over any time horizon. Factors mortgage interest, tax, maintenance, appreciation and opportunity cost. Debt Payoff Calculator Enter credit cards and loans, choose a total monthly payment, and see when you'll be debt-free. Compare the snowball and avalanche methods side by side. US Income Tax Calculator (2024) Estimate your 2024 US federal income tax, effective rate and marginal bracket. Supports single, MFJ, MFS, HoH with the standard deduction. VAT Calculator Add VAT to a net price or remove VAT from a gross price. Supports UK 20%, Ireland 23%, Germany 19%, France 20% and every EU rate — plus custom %. Break-Even Point Calculator Find how many units you need to sell to cover fixed costs. Enter costs, price and unit variable cost — get break-even, revenue and target-profit units. Markup & Margin Calculator Convert between cost, markup, margin and selling price. Enter any two and get the other two instantly. Handy for pricing and margin/markup conversion. UK Stamp Duty Calculator (SDLT) Work out UK Stamp Duty Land Tax on a property purchase. Covers standard buyers, first-time buyers and additional/buy-to-let, with band-by-band breakdown. Freelance Hourly Rate Calculator Work out the hourly rate you need to charge as a freelancer. Factors target take-home, tax, expenses, holiday, sick days and non-billable time. UK Take-Home Pay Calculator (Salary After Tax) Work out your UK take-home pay after Income Tax, NI, pension and student loan. Get monthly, weekly and hourly net pay with a full breakdown. UK Salary Sacrifice Calculator (Pension) See how much extra pension you get — and how little your take-home actually drops — with salary sacrifice. Shows the NI saving in £ terms. UK Capital Gains Tax Calculator (Shares & Property) Work out your UK Capital Gains Tax for 2024/25 on shares, funds or property. Handles the £3,000 exempt amount and shares vs property rates. UK Dividend Tax Calculator (Company Director / Investor) Work out UK dividend tax for 2024/25. Handles the £500 allowance, Personal Allowance interaction, and the 8.75/33.75/39.35% rates. ISA vs GIA Calculator (UK Investment Tax Savings) See how much tax you save with a Stocks & Shares ISA vs a General Investment Account over 10, 20 and 30 years. Models dividend + capital gains tax. SIPP Tax Relief Calculator (UK Pension Contributions) Work out the real cost of your SIPP contribution after tax relief. Handles basic, higher, additional, Scottish and the £100k taper trick. 2024/25. Tapered Annual Allowance Calculator (UK Pension, 2024/25) Work out your tapered pension Annual Allowance for 2024/25. Enter threshold income and adjusted income — get your personal AA, taper, and the maximum contribution before an Annual Allowance Charge kicks in. Child Benefit Tax Charge (HICBC) Calculator — 2024/25 UK Free 2024/25 HICBC calculator with the new £60k–£80k thresholds. Enter salary, pension and number of kids — see your Child Benefit clawback, effective marginal rate, and the exact pension top-up that eliminates the charge. Lump Sum Allowance Calculator (LSA £268,275) — 2024/25 UK Pension The Lifetime Allowance was abolished in April 2024. Work out your Lump Sum Allowance (£268,275) and Lump Sum & Death Benefit Allowance (£1,073,100) — how much of your pension you can actually take tax-free. Pension Carry Forward Calculator — 3-Year Unused Annual Allowance (2024/25) Work out how much unused pension Annual Allowance you can carry forward from the last 3 years. Handles the £40k→£60k change, tapering, and oldest-first ordering to show your maximum contribution this year. Bonus Sacrifice Calculator — Put Your Bonus Into Your Pension (2024/25 UK) Should you take your bonus as cash or sacrifice it into your pension? See the take-home you give up vs the pension value you gain — including the £100k trap (60% relief), Child Benefit rescue, and employer NI uplift. 2024/25 UK. Lifetime ISA (LISA) Calculator — £1,000 Government Bonus See the LISA government bonus (up to £1,000/year), your projected pot at 60 or first-home purchase, and whether the 25% penalty leaves you worse off. UK Total Compensation Calculator (Job Offer True Value) Compare two UK job offers on true total value: base + pension, sacrifice tax savings, RSUs / ESPP, medical BiK, bonus and holiday value. UK Marriage Allowance Calculator Find out whether you and your partner can claim the Marriage Allowance, and how much you'd save from transferring £1,260 of Personal Allowance. UK Self-Employed Tax Calculator (Sole Trader) Work out the Income Tax and National Insurance (Class 2 & 4) you'll owe as a UK sole trader. Get your bill, take-home and payment-on-account. Scottish Take-Home Pay Calculator (Salary After Tax) Work out Scottish take-home pay after Scottish Income Tax, NI, pension and student loan. All six 2024/25 Scottish bands, starter through top. International Money Transfer Cost Calculator See what your bank is really costing you on international transfers vs a mid-market provider (FX markup + fees) and what more the recipient gets.

Math

Percentages, ratios and quick math helpers.

Percentage Calculator Quickly work out a percentage of a number, what percent one number is of another, and the percentage increase or decrease between two values. Scientific Notation Calculator Convert numbers between standard, scientific and engineering notation. Round to significant figures and add, subtract, multiply or divide in sci-not. Average Calculator Calculate the mean, median, mode, and range of any set of numbers. Enter your numbers separated by commas and get instant statistical results. Fraction Calculator Add, subtract, multiply, and divide fractions. Simplify fractions to lowest terms and convert between fractions and decimals.

Health

Body, fitness and wellbeing calculators.

BMI Calculator Calculate your Body Mass Index in metric or imperial units. See your BMI category and where you fall on the standard weight classification scale. Sleep Calculator Find the best time to sleep or wake up based on 90-minute REM cycles. Wake up refreshed instead of groggy — bedtime and wake-time calculator. Calorie / TDEE Calculator Work out your BMR and Total Daily Energy Expenditure (TDEE) with the Mifflin-St Jeor formula. See the calories to maintain, lose or gain weight. Pace Calculator Calculate running pace, speed, distance, or time. Supports miles and kilometres. Find out how fast you need to run for a target race time. Water Intake Calculator Calculate how much water you should drink each day based on your weight, activity and climate. Get a target in ml, litres or cups. Body Fat Percentage Calculator Estimate your body-fat percentage using the US Navy method — tape-measure your waist, neck and (for women) hips. See where you land on the scale.

Everyday

Handy tools for day-to-day life.

Tip Calculator Calculate how much to tip on any restaurant bill. Choose your tip percentage, split it between any number of people, and see exactly what each person pays. Age Calculator Find your exact age in years, months, and days from any birth date. See your next birthday countdown and discover what day of the week you were born. Unit Converter Convert between units of length, weight, temperature, volume, area, and speed instantly. Metric and imperial units — just type a value and get the answer. Currency Converter Convert between 160+ world currencies using live exchange rates. Fast, free, and updated automatically. Discount Calculator Calculate the sale price after a percentage discount, the amount you save, and the discount percentage from original and sale prices. GPA Calculator Calculate your weighted GPA from letter grades and credit hours. Supports 4.0, percentage, and letter grade scales. Date & Time Difference Calculator Find out exactly how many days, weeks, months, and years are between two dates. Also calculate hours and minutes between two times. Word & Character Counter Count words, characters, sentences, and paragraphs in any text. Get an estimated reading time and speaking time. Sales Tax Calculator Calculate the final price after sales tax, find the pre-tax price from a total, or work out the tax rate. Supports any tax percentage. IPv4 Subnet Calculator IPv4 subnet calculator: network and broadcast address, usable host range, mask, wildcard mask and host count for any CIDR block. Prefix ↔ dotted-decimal.

Can't find what you need?

If a calculator you'd expect to find here doesn't exist yet, drop us a note on the contact page. We regularly build new tools based on reader requests, and if you can describe the question clearly there's a good chance it'll show up in the next release.

Content on CalcOrchard is for general information and education only. It is not tax, medical, legal, or financial advice. Always consult a suitably qualified professional before making decisions based on any output from this site.