How we build and check our calculators

Where our numbers come from

We use official, primary sources wherever one exists and link to it on the tool itself. For finance and tax we rely on government and central-bank data — the IRS and HUD in the US, HMRC in the UK, the CRA in Canada and the ATO in Australia — plus published lender disclosures and the Freddie Mac Primary Mortgage Market Survey for rates. For health and fitness we use the WHO, CDC and NHS. For trade and engineering tools we use manufacturer data and national standards. We date every figure that changes over time and refresh it on a schedule (see below).

How we build each tool

Before a calculator is written we audit the live top-5 search results for its main query and extract the real questions people ask, the inputs the best tools expose, and the gaps none of them fill. Each Calcuris tool then has to do something the incumbents do not: a complete, multi-step engine for one clear intent, a proprietary visualisation, export (CSV/PDF), local accuracy for the US, UK, Canada and Australia, and a direct answer up top. The formula is shown in plain text on the page so you can check our working — we would rather show the maths than hide it.

How we check accuracy

Outputs are validated against worked examples and standard references (for example NIST and OpenStax for maths). A second member of the team fact-checks the figures and formula before publication, and the page records who reviewed it and when. When a reader flags an error we fix it and update the “last updated” date. We treat a wrong number as a bug, not a rounding detail.

How often we update

Rates and statutory figures move, so we separate them from the logic. Mortgage and savings rates track the latest weekly survey; tax brackets, contribution limits and program fees are updated each tax year or when an authority publishes a change. Every page shows the date its data reflects. If a figure looks stale, the date will tell you.

Who builds Calcuris

Researched & verified by the Calcuris Data & Research Team. Our analysts each own a family of tools:

• Daniel Okafor — Financial Data Analyst, Calcuris Research. Daniel builds and stress-tests Calcuris's finance models (mortgages, loans, tax, retirement). He compiles each tool's figures from primary sources — IRS/HMRC/CRA/ATO schedules, lender disclosures and central-bank data — and documents every formula on our methodology page.
• Sarah Mitchell — Quantitative Analyst, Calcuris Research. Sarah, a former mathematics teacher, designs Calcuris's math, statistics and education tools so each one shows its full working, not just an answer. She validates outputs against standard references (NIST, OpenStax) and worked examples.
• Emily Carter — Health Data Analyst, Calcuris Research. Emily curates the data behind Calcuris's health and fitness estimators (BMI, calories, due date) from public sources such as the WHO, CDC and NHS. Calcuris provides educational estimates only — never a diagnosis or medical advice — and every health tool says so plainly.
• James Whitfield — Engineering & Data Analyst, Calcuris Research. James handles Calcuris's practical and trade tools (concrete, electrical, fuel, sizing, immigration points). He cross-checks material yields and unit conventions against manufacturer data and national standards for the US, UK, Canada and Australia.

What Calcuris is not

We are analysts and researchers, not your accountant, doctor or lawyer, and we do not claim clinical, legal or licensed financial authority. Our calculators are educational estimates based on the values you enter and current published figures. For decisions that carry real consequences — a loan you will sign, a medical question, a tax filing — confirm the result with a qualified professional. Where a topic is sensitive (money, health, law) we say so on the page and keep the disclaimer in plain sight.