Contact details
Response time
1–2 business days
We aim to reply to every message
Based
Online — serving globally
All calculators are free and browser-based
Your data is never shared
Real human replies
Bugs fixed fast
Ideas welcome
What to write about
Formula error or wrong result
Calculator or tool request
Which formula applies to your situation
Guide feedback or content improvement
Collaboration or contribution
Anything else on your mind
Send us a message
Fill in the form and we'll get back to you promptly.
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Message received!
Thanks for getting in touch. We'll reply to within 1–2 business days.
← Back to calculatorsQuick answers
Can I request a specific calculator?
Absolutely — calculator requests are our favourite messages. Tell us what you need and why, and we'll prioritise accordingly.
I think there's an error in a formula — what should I do?
Please report it with the page URL and your expected result. We take formula accuracy seriously and will investigate and fix it quickly.
Are the calculators really free?
Yes — completely free, forever. No sign-up, no paywall, no subscription. All calculators run in your browser.
Can I use the calculators or formulas in my own work?
Yes — the formulas are standard industry methodology. Feel free to use them. If you reference our site, we'd appreciate a link but it's not required.
I'm not sure which formula to use — can you help?
Yes. Use the form above, select "Which formula should I use?" and describe your situation. We'll point you to the right approach and calculator.
Do you offer consulting or custom work?
We don't currently offer consulting, but if you have a specialised need, reach out anyway — we're happy to point you in the right direction.