About DeckFormula
DeckFormula is a small reference site for people building or repairing a deck. It exists because most deck calculators will give you a number but not the formula, the assumptions, or the cases they cannot handle.
What this site is
A set of seven calculators and two reference pages covering decking quantity, joist layout, railing, stairs, footings, cost and lumber volume. Every tool shows its arithmetic and states its limits.
What this site is not
- Not a design service. We do not produce plans, and we do not review yours.
- Not a code authority. We cite the IRC where a number comes from it. Your building department decides what applies.
- Not an engineering reference. Structural sizing is deliberately out of scope.
- Not a marketplace. We do not sell decks, materials or leads.
How the site is run
It is run by a small editorial team. We are not contractors, and we do not pretend to be — the value we offer is careful arithmetic and honest scoping, not jobsite experience. Where a question needs a licensed professional, we say so instead of answering it badly.
Funding comes from advertising placement, disclosed separately. No advertiser sees a calculator before it publishes, and none has input into a formula or a recommendation.
How to tell whether to trust a number here
Do not trust it — check it. Every page shows the formula and a worked example with real numbers. If you can reproduce the example with a pencil, the arithmetic is sound. If the inputs match your site, the answer is right for your site. Those are two separate checks, and both are yours to make.
Contact
Corrections, discrepancies and complaints are welcome and are the most useful thing you can send. Write to the address on the methodology page, and include the inputs you used so we can reproduce the result.
Questions people actually ask
Who writes this site?
A small editorial team, named on request. We are not contractors, and we do not claim jobsite experience — the site is built on published formulas and code, not on field anecdotes.
Is DeckFormula affiliated with any deck builder or retailer?
No. The site takes no payment for placement or recommendation. Advertising is disclosed, and no advertiser has input into a result.
Can I use these calculators for a commercial project?
The arithmetic applies, but commercial work is governed by different code provisions — guard height and occupancy loads in particular. Verify against the code your jurisdiction applies to commercial structures.