Affiliate disclosure
This site is free to use. It earns money when you buy through some of its product links, at no extra cost to you.
How it works
Some links to retailers and manufacturers are affiliate links. If you follow one and buy, the retailer pays this site a commission. The price you pay is the same.
In calculator results, affiliate links are the "Check price" buttons. Every one carries the
rel="sponsored" tag, which tells search engines it is a paid link.
What commissions do not change
- Calculator results. Every figure comes from the formulas shown on each calculator page. No product or retailer affects them.
- Which products are shown. Products appear because they meet the spec the calculator worked out, not because of their commission rate.
- Placement. We do not accept payment for placement or for reviews.
Last updated 15 October 2026.