How HowMuchDoINeed.co Compares
There are some great construction and DIY calculators out there — Omni Calculator, Inch Calculator, Blocklayer and more. Here is an honest look at how we stack up, and where we do a little more for you: metric or imperial units, UK and US terminology, built-in costs, and everything in one project.
| Calculator site | Free with no paywall | Metric & imperial + UK/US terminology | Material quantity estimates | Built-in cost / price estimator | Labour & extra costs included | Multi-tool Project Builder (combined shopping list) | No sign-up required |
|---|---|---|---|---|---|---|---|
HowMuchDoINeed.co 140+ calculators that work anywhere — metric or imperial, UK or US terms — with quantities and costs in one place. | |||||||
Omni Calculator A huge global library with metric/imperial support, but no combined project list. | |||||||
Inch Calculator Strong, practical tools but imperial-first and US-oriented. | |||||||
Blocklayer Detailed diagrams and metric/imperial support, but a dated interface and no cost planning. | |||||||
Calculator.net Reliable general-purpose maths, but limited construction depth and one terminology. | |||||||
MaterialCalculator.co.uk A genuine UK option with project estimators, but UK-only terms and a smaller range of tools. | |||||||
CalcPros (UK) Good UK Building-Regs references, but UK-only and no cost estimator or project list. | |||||||
RapidTables Great for technical and engineering maths, not material shopping lists. | |||||||
HomeProjectCalculator.com A wide range of tools but US-leaning units and no combined project builder. | |||||||
Retailer calculators (e.g. Home Depot) Tied to one store’s range and pricing, often US-only. |
Comparison based on publicly available information about each site’s typical experience at the time of writing. Other sites are trademarks of their respective owners and may add or change features — always check their latest offering. We’ve tried to be fair; if you think we’ve got something wrong, please let us know.
Why people choose us
Metric, imperial, UK & US
Every calculator works in both metric and imperial units and uses UK and US terminology, with sensible material sizes, coverage rates and waste allowances — wherever in the world you are building.
Quantities and costs together
Most sites stop at how much you need. We add an optional cost estimator — including labour and extras like delivery or hire — so you can budget in the same place.
One project, many trades
Our Project Builder lets you add results from several calculators into a single combined shopping list — handy when a job spans concrete, timber and paint.
Free and no sign-up
All 140+ calculators are free with nothing to install and no account needed. Open a tool, get your answer, get on with the job.
Frequently asked questions
Is HowMuchDoINeed.co really free?
Yes. Every one of our 140+ calculators is free to use with no sign-up. You only pay if you choose the optional Project Pack, which bundles and exports a full multi-trade shopping list — the calculators themselves always stay free.
What makes it a good alternative to Omni Calculator or Inch Calculator?
Those are excellent, well-known tools, but they usually stop at quantities and lean towards one region’s terminology. HowMuchDoINeed.co works in metric or imperial with both UK and US terminology, pairs every quantity with an optional cost estimate including labour and extras, and lets you combine several calculators into one project.
Do your calculators work in both metric and imperial, and for UK and US users?
Yes. Every calculator supports both metric and imperial units and uses both UK and US terminology, with sensible material sizes, coverage rates and waste allowances — so the results make sense whether you are ordering from a merchant in Britain, the US or anywhere else.
How accurate are the estimates compared with other sites?
We use the same standard trade formulas the best calculators rely on, plus adjustable waste allowances. As with any online calculator, results are planning estimates rather than professional advice — always confirm with your supplier or a qualified tradesperson before ordering.
See the difference for yourself
Pick a calculator, get your quantities and a cost estimate in seconds — free, no sign-up.
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