Contact
Found a number that looks wrong, or a tool that should exist? Corrections come first.
Replace this address with a monitored mailbox before publishing. We aim to reply within two business days.
Report a calculation error
Please include the page URL, the inputs you used, the result you got, and the result you expected. If you can cite a source — the IRS instructions, an ACI or NRMCA reference, a building code section — that speeds things up a lot.
Confirmed errors are fixed on the page and noted in the change log on the methodology page.
Suggest a tool
Tell us what you were trying to work out, what you used instead, and what was missing. Suggestions that come with a real workflow (“I bid decks and need board feet plus waste plus fastener counts”) are the ones that get built.
What we cannot help with
- Individual tax or legal advice. We can explain how a formula works, but not whether a deduction applies to your situation. Talk to a CPA or enrolled agent.
- Contractor quotes or structural sign-off. Concrete and lumber quantities are estimates; a licensed professional has to approve anything structural.
- Ad or billing questions. Ads are served by third parties; use the ad provider's own reporting and support channels.
Privacy
Messages sent by email are stored in the mailbox they were sent to. Nothing you type into a calculator is transmitted or stored — see the privacy policy.