Steven Stewart

Founder and editor, Numwise

Steven Stewart runs Numwise from the UK. He builds each calculator, checks the figures against official sources such as Ofgem, HMRC and GOV.UK, and works through example sums by hand before a page goes live.

He started Numwise because so many online calculators use American sizes, out-of-date prices or figures with no source. Every page here says where its numbers come from and when they were last checked, and he updates prices when they change, starting with the energy price cap every quarter.

How Steven checks a calculator

  • Finds the official figure first: Ofgem for energy, HMRC and GOV.UK for rates and rules, manufacturers for sizes and coverage.
  • Works through example sums by hand and checks the calculator gives the same answer.
  • Records the source and the date on the page, and rechecks it when the figure is due to change.

Read the full editorial policy.

Calculators by Steven

Home & DIY

Energy & bills

Pets

Motoring & EV

Money & pay

Contact Steven

Email hello@numwise.co.uk.