About CalcBeast
CalcBeast is a collection of practical calculators for decisions that usually start with a quick search: how much an appliance costs to run, whether a home upgrade might pay back, or what a bill could look like after changing the assumptions. The first group of tools focuses on UK energy costs because small differences in unit rates, hours of use, and efficiency can change the answer quickly.
Each calculator is built around one job. We try to keep the inputs understandable, show the assumptions beside the result, and avoid hiding the useful part behind a form submission. If a default figure is used, such as an electricity unit rate, boiler efficiency, or battery round-trip efficiency, the page should make it clear enough for you to replace it with your own number.
The site is static and the calculators run in your browser. You do not need an account, and the core calculation does not depend on a paid API. That keeps the tools quick to load and cheap to operate, which matters for a site made of simple, repeat-use calculators.
How our estimates work
A good calculator is only useful if the result is easy to question. Our pages are written to expose the moving parts: usage, rate, efficiency, billing period, installation cost, savings, and payback where relevant. The estimate should help you compare options before you spend time on quotes or spreadsheets.
Accuracy
CalcBeast is designed for practical planning, not professional sign-off. Energy tariffs, VAT treatment, standing charges, installer prices, household usage, and product performance all vary. Use the results to sense-check a decision, then confirm important figures against your own bills, a supplier quote, an installer, or a qualified adviser before you commit.
How the site is funded
We do not charge for the calculators. If the site grows, advertising or affiliate links may help cover hosting, domain, and maintenance costs. That should not change the result a calculator gives you, and commercial links should be labelled where they appear.