Calc Garden

Guides

Short, practical guides that explain the maths behind our calculators so the numbers make sense. Each one links straight to the matching tool so you can run your own figures.

Money & Finance

Free Legal & General life insurance calculator alternative

How Calc Garden's DIME-method life insurance needs calculator compares with the Legal & General cover calculator, Aviva and Drewberry, with a worked UK example and an honest table of where each one wins.

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Money & Finance

Best free UK student loan repayment calculator

Which free UK student loan repayment calculator to use, with the 2026/27 thresholds for Plans 1, 2, 4, 5 and Postgraduate and an honest table comparing Calc Garden, student-loan-calculator.co.uk, The Salary Calculator and your SLC account.

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Money & Finance

Best free simple interest calculator (no signup)

Which free simple interest calculator to use, with an honest table comparing Calc Garden, Calculator.net, CalculatorSoup and NerdWallet on reverse-solving, time units, charts and privacy.

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Everyday & Shopping

Best free unit price calculator for grocery shopping

Which free unit price calculator to use for grocery shopping, comparing Calc Garden, Omni, PricePerPiece and Bang Your Buck on units, items and savings.

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Home & Garden

Best free tile calculator (no signup)

Which free tile calculator to use, with an honest table comparing Calc Garden, Omni Calculator, Calculator.net and Topps Tiles on waste allowance, grout gaps, boxes and cost.

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Education

Best free fraction calculator (no signup)

Which free fraction calculator to use, with an honest table comparing Calc Garden, Calculator.net, CalculatorSoup and Mathway on mixed numbers, step-by-step working and live results.

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Health & Fitness

Best free water intake calculator (no signup)

Which free water intake calculator to use, with an honest table comparing Calc Garden, GigaCalculator, calculator-online.net and thewaterintakecalculator.com on inputs, climate adjustment and glasses.

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Everyday & Shopping

Best free time card calculator (no signup)

Which free time card calculator to use, with an honest table comparing Calc Garden, Clockify, Redcort and timecardcalculator.net on single-shift speed, weekly grids, overtime and pay.

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Money & Finance

Best free ROI calculator (no signup)

Which free ROI calculator to use, with an honest table comparing Calc Garden, Calculator.net, Omni and CalculatorSoup on annualised ROI, dates, cost fields and privacy.

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Health & Fitness

Best free heart rate zone calculator (no signup)

Which free heart rate zone calculator to use, with an honest table comparing Calc Garden, Omni, Calculator.net and McMillan on zones, the Karvonen method and formula clarity.

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Health & Fitness

Free alternative to the Calculator.net ideal weight tool

Calc Garden is a free, no-signup set of online calculators that give instant finance, salary and fitness results with the formula shown.

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Money & Finance

Free Zillow down payment calculator alternative

How Calc Garden's free, no-signup down payment calculator compares to the Zillow down payment calculator, with an honest feature table and where each one wins.

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Money & Finance

Best free emergency fund calculator (no signup)

Which free emergency fund calculator to use, with an honest table comparing Calc Garden, Empower, NerdWallet and PNC on shortfall, months covered and savings plans.

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Health & Fitness

Best free calories burned calculator (no signup)

Which free calories burned calculator to use, with an honest table comparing Calc Garden, Calculator.net, Omni and WebMD on the MET method, activity count and adjustments.

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Money & Finance

Best free mortgage affordability calculator (UK)

Which free mortgage affordability calculator to use to see how much you can borrow, with an honest table comparing Calc Garden, MoneyHelper, MoneySavingExpert and bank calculators.

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Health & Fitness

Best free running pace calculator (no signup)

Which free running pace calculator to use, with an honest table comparing Calc Garden, McMillan, Strava and calculator.net on scope, race prediction, training paces and clarity.

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Money & Finance

Best free net worth calculator (no account needed)

Which free net worth calculator to use, with an honest table comparing Calc Garden, Empower, NerdWallet and Bankrate on signup, account linking, privacy and tracking.

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Health & Fitness

Best free sleep cycle calculator to wake up rested

Which free sleep cycle calculator to use, with an honest table comparing Calc Garden, calculator.net and Sleepopolis on 90-minute cycles, customisation and clarity.

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Health & Fitness

Best free US Navy body fat calculator

Which free US Navy body fat calculator to use, with an honest table comparing Calc Garden, Omni and calculator.net, plus the 2026 move to waist-to-height ratio.

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Business & Work

Free Shopify profit margin calculator alternative

How Calc Garden's free, no-signup profit margin calculator compares to the Shopify profit margin calculator, with an honest feature table and where each one wins.

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Home & Garden

Free Dulux paint calculator alternative

How Calc Garden's free, no-signup paint calculator compares to the Dulux paint calculator, with an honest feature table and where each one wins.

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Health & Fitness

Free BabyCenter due date calculator alternative

How Calc Garden's free, no-signup pregnancy due date calculator compares to the BabyCenter due date calculator, with an honest feature table and where each one wins.

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Everyday & Shopping

Free Avalara sales tax calculator alternative

How Calc Garden's free, no-signup sales tax calculator compares to the Avalara sales tax calculator, with an honest feature table and where each one wins.

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Health & Fitness

Free Precision Nutrition macro calculator alternative

How Calc Garden's free, no-signup macronutrient calculator compares to the email-gated Precision Nutrition Ultimate Macro Calculator, with an honest feature table and where each one wins.

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Money & Finance

Free Bankrate credit card payoff calculator alternative

How Calc Garden's free, no-signup credit card payoff calculator compares to the Bankrate tool, with an honest feature table and where each one wins.

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Money & Finance

Free alternative to the NYT rent vs buy calculator

How Calc Garden's free, no-signup rent vs buy calculator compares to the paywalled New York Times rent versus buy tool, with an honest feature table and where each one wins.

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Money & Finance

Free Bank of England inflation calculator alternative

How Calc Garden's forward-projection inflation calculator compares to the Bank of England's official historical CPI lookup, with an honest feature table and where each tool wins.

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Money & Finance

Free alternative to the Bankrate savings goal calculator

How Calc Garden's savings goal calculator, which shows how long a target takes to reach, compares to the Bankrate tool that solves for the monthly amount, with an honest feature table.

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Money & Finance

The 4% Rule: How Big a Pot You Need to Retire

What the 4 percent rule means, why it implies a pot of about 25 times your annual spending, how inflation fits in, and the caveats to plan around.

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Health & Fitness

What Is a Good BMI, and What It Doesn't Tell You

A good adult BMI is 18.5 to 24.9, but it is only a rough screen. How to read your number and the limits BMI does not show.

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Money & Finance

APR vs Interest Rate: What's the Difference?

Understand APR vs interest rate: why APR includes fees, what representative APR means, and how to compare loans on the true yearly cost.

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Everyday & Shopping

Free alternative to The VAT Calculator (UK)

Add or remove UK VAT at 20 percent or any rate, with the net, VAT and gross amounts shown side by side. Free and instant, no sign-up.

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Everyday & Shopping

Free alternative to the Calculator.net discount calculator

Work out a sale price and exactly how much you save from any percentage discount, with the maths shown. Free and instant, no sign-up.

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Everyday & Shopping

Free alternative to the Sust-it electricity calculator

Estimate what an appliance costs to run from its wattage, hours of use and your unit rate. Free electricity cost guide and calculator.

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Everyday & Shopping

Free alternative to the Calculator.net tip calculator

Split a bill and add a tip in seconds, with clear per-person totals for any group size. Free tip calculator, no sign-up needed.

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Money & Finance

How Compound Interest Works

A plain-English guide to compound interest: the formula, why compounding frequency matters and how to use it to grow savings over time.

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Money & Finance

Free alternative to NerdWallet and SmartAsset calculators

Free mortgage, loan and retirement calculators that show the full numbers behind the answer, with no sign-up and no account required.

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Money & Finance

Best free mortgage calculator that shows total interest

See your monthly mortgage payment and the total interest over the full term, not just the headline rate. Free, instant, no sign-up.

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Money & Finance

Free alternative to Empower retirement planner

Project when you could retire from your savings, monthly investing and target spend. Free retirement planning guide and calculator.

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Money & Finance

Free alternative to the Bankrate auto loan calculator

Work out monthly car loan repayments and the total interest you will pay over the term. Free auto loan guide and calculator.

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Money & Finance

Free alternative to the BLS inflation calculator

See how inflation changes the buying power of money over time, with a clear worked example. Free inflation guide and calculator.

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Money & Finance

Free alternative to The Salary Calculator (UK)

Estimate your UK take-home pay after income tax and National Insurance from your gross salary. Free, instant, no sign-up.

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Health & Fitness

Free alternative to the Calculator.net TDEE calculator

Estimate your daily calorie needs from your BMR and activity level, with the formula explained. Free TDEE guide and calculator.

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Money & Finance

Free alternative to the SBA break-even calculator

Find the break-even point for a small business from fixed costs, price and variable cost per unit. Free guide and calculator.

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Health & Fitness

Free alternative to the Calculator.net BMI calculator

Work out your BMI from your height and weight and see which category it falls in. Free BMI guide and calculator, no sign-up.

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Money & Finance

Free Investor.gov compound interest calculator alternative

See how savings grow with compound interest over time, with the formula and a worked example. Free guide and calculator.

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Money & Finance

Free alternative to the Talent.com salary converter

Convert an hourly wage to a yearly salary, or a salary back to an hourly rate, in seconds. Free salary converter guide and calculator.

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Everyday & Shopping

Free alternative to the RAC fuel cost calculator

Estimate the fuel cost of any journey from distance, fuel economy and pump price. Free fuel cost guide and calculator.

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Everyday & Shopping

Free alternative to the Calculator.net age calculator

Work out an exact age in years, months and days between any two dates. Free age calculator guide, instant and no sign-up.

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Everyday & Shopping

Free alternative to the Omni Calculator percentage tool

Find a percentage of a number, or add and subtract a percentage, with the working shown. Free percentage guide and calculator.

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Education

Free alternative to the Calculator.net GPA calculator

Work out a weighted GPA on the 4.0 scale from your course grades and credit hours. Free GPA guide and calculator.

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Money & Finance

The Rule of 72: How Fast Does Money Double?

How the Rule of 72 estimates doubling time, why 72 is the magic number, when to use 69.3 or 70 instead, and a quick mental-maths table for common rates.

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Money & Finance

CAGR vs Average Return: Why They Differ

Why CAGR is almost always lower than a simple average return, the +100% then -50% example that proves it, and which measure to trust for real investments.

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Money & Finance

What Is a Good Debt-to-Income Ratio?

What counts as a healthy debt-to-income ratio, the exact formula, the under-36% / 37-43% / over-43% bands, and how clearing a card lowers your DTI.

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Health & Fitness

How Much Protein Do You Need a Day?

Protein needs by goal in grams per kg: 0.8 g/kg to maintain, 1.2 to 1.6 g/kg active, 1.6 to 2.0 g/kg to build muscle, with a worked example.

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Health & Fitness

What Is a Healthy Waist-to-Height Ratio?

A healthy waist-to-height ratio is about 0.4 to 0.49: the keep-your-waist-under-half-your-height rule. How to measure it and read it alongside BMI.

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Health & Fitness

How to Calculate Your One-Rep Max (1RM)

Estimate your one-rep max with the Epley formula 1RM = weight x (1 + reps/30), plus Brzycki, a worked example and a percentage-of-1RM training table.

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Business & Work

Margin vs Markup: The Difference (With Examples)

Markup is profit over cost; margin is profit over price. See the conversion table, worked GBP examples, and how to price from a target margin.

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Home & Garden

How Much Soil for a Raised Bed? (UK Bag Guide)

Work out raised bed soil: length x width x depth in metres, then convert to litres and 50L bags. Worked example plus the ideal topsoil and compost mix.

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Home & Garden

How Much Concrete for a Shed Base? UK Guide

Work out concrete for a shed base: length x width x 0.1 m for 100 mm, plus 10 percent waste. Worked example, the C20 1:2:4 mix, and bags vs ready-mix.

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Education

What Grade Do I Need on My Final Exam?

Work out the exact mark you need on your final exam with one formula, three worked examples, and a quick way to find the final's weight.

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Education

Population vs Sample Standard Deviation

When to divide by N versus n minus 1 for standard deviation, why Bessel's correction matters, a worked example, and STDEV.P vs STDEV.S.

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Everyday & Shopping

Are Bigger Pizzas Better Value?

Why a bigger pizza is often the better deal: pizza scales by area, an 18-inch can beat two 12-inch, and how to compare price per square inch.

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