CalcKit — Free UK Calculators
29+ Free UK Calculators

Free UK Business &
Finance Calculators

Instant, accurate calculators for UK businesses, freelancers, and homeowners. No signup. Always free.

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Profit Margin Calculator

Free UK gross margin calculator and business margin calculator for UK businesses. Enter revenue and costs to see the gross margin formula result and net margin formula result instantly — both expressed as a percentage of total revenue. Works as a gross profit calculator, a profit calculator uk, and a margin calculator uk in one. Essential for tracking financial health, benchmarking margin percentage, and managing operating costs across product lines.

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UK VAT Calculator — Add or Remove VAT

Free online VAT calculator for UK businesses and individuals. Add VAT to any net amount or remove VAT from a gross amount instantly. Supports all UK VAT rates — standard 20%, reduced 5%, and zero rate. Use the reverse VAT calculator uk to find the net amount from a gross price, or work out the VAT portion on any products and services. Essential for completing your VAT return, checking invoices, or calculating the gross amount VAT-inclusive on a quote.

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Income Tax Calculator UK 2025/26 — Take Home Pay

Free income tax calculator UK 2025/26 — the most complete take home pay calculator uk available. Find your exact salary after tax, National Insurance contributions, and any other deductions. Use it as a PAYE calculator, a tax calculator take home pay tool, a net pay calculator uk, or a gross income calculator. Wondering how much do i take home on a specific salary? Use this to check 45k after tax, 65000 after tax, 85k after tax, 90k after tax, or any other amount. Model a pay rise, check your tax code, and understand exactly how much would i earn after tax on any income.

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Freelancer Day Rate Calculator

Find out exactly what day rate and hourly rate to charge as a UK freelancer based on your desired annual income, tax, and expenses. Works as a freelance salary calculator too — reverse-calculate the salary equivalent of any day rate.

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UK Stamp Duty Calculator 2025 — SDLT Land Tax

Find out exactly how much stamp duty land tax (SDLT) you will pay on any residential property or land purchase in England. Updated for April 2025 SDLT rates. Covers standard purchases, first-time buyer relief, second home surcharge, and buy-to-let properties. Stamp duty is calculated in bands — this calculator applies the correct rate to each portion automatically, so any UK resident can quickly work out their total SDLT liability before making an offer.

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UK Mortgage Affordability Calculator — How Much Can I Borrow?

Free mortgage calculator UK — use this calculator to work out how much you can borrow based on your salary and deposit. This mortgage affordability calculator uk uses the standard 4–4.5x income multiple UK mortgage lenders apply. Includes a mortgage repayment calculator for regular monthly payment estimates, interest only mortgage comparison, overpayment of mortgage calculator to model overpayments and remaining term reductions, and life insurance cost guidance. Also works as a mortgage calculator how much can i borrow tool for joint applications.

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Mortgage Overpayment Calculator UK — See How Much You Save

Free mortgage overpayment calculator UK — enter your mortgage balance, interest rate, remaining term, and monthly overpayment to see exactly how much interest you save and how many years you knock off your mortgage. Supports both monthly overpayments and one-off lump sum payments. Includes an overpayment comparison table so you can instantly compare the savings from £100, £200, or £500 extra per month. Most UK lenders allow up to 10% of the outstanding balance overpaid each year without an early repayment charge — this calculator helps you model that benefit.

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UK BMI Calculator — Body Mass Index (NHS)

Free BMI calculator for UK adults. Use this BMI calculator to find your BMI and check if you are a healthy weight. This BMI calculator works for women and men. Enter your height and weight and your estimated BMI appears in seconds. You will also see your NHS weight category and your healthy weight range for your height. BMI is a useful guide, but it is just one piece of the picture. It does not measure body fat directly. Muscle, age, and body shape all affect what your number really means.

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Sleep Calculator

Find the optimal times to wake up based on 90-minute sleep cycles so you wake feeling refreshed instead of groggy.

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Why Use CalcKit?

Built specifically for UK businesses and individuals. All calculators use current 2025/26 rates and are updated regularly. Learn more about CalcKit →

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Always Free
No subscriptions, no limits
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UK Focused
Current HMRC rates & rules
Instant Results
No forms or sign ups
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Mobile Ready
Works on any device

Free UK Calculators for Every Situation

CalcKit provides free, instant online calculators built specifically for the UK. Whether you are a sole trader working out your take-home pay, a landlord calculating rental yield on a buy-to-let, a small business owner checking your break-even point, or a first-time buyer estimating stamp duty — there is a calculator here for you.

Every financial calculator uses the current 2025/26 HMRC rates and thresholds, including the £12,570 personal allowance, income tax bands at 20%, 40%, and 45%, and National Insurance at 8% up to £50,270 and 2% above. VAT calculators cover all three UK rates: standard 20%, reduced 5%, and zero rate. Stamp duty figures reflect the April 2025 rate changes.

All calculations happen instantly in your browser. No data is ever sent to our servers, no account is required, and there are no hidden fees. We update all rates at the start of each UK tax year so you always get accurate results. Browse all 29 free calculators →

UK Tax & Finance — Key 2025/26 Rates

Rates for 2025/26 tax year. Source: HMRC and GOV.UK.

Who Are These Calculators For?

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Sole Traders & Freelancers

Calculate your take-home pay after income tax and Class 4 National Insurance. Work out a day rate that covers your tax bill, holiday pay, and expenses. Check your IR35 status and its financial impact.

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Small Business Owners

Find your break-even point, calculate profit margins, add VAT to invoices, and measure ROI before committing to any spend.

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Homebuyers & Landlords

Estimate stamp duty before you make an offer, check your mortgage affordability, and calculate rental yield on buy-to-let investments.

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Health & Wellbeing

Check your BMI using NHS classifications, find your daily calorie needs, optimise your sleep schedule, and track your water intake.

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