Concrete footing calculator

Non-positive length, width, or depth—and a non-positive or non-integer count—are rejected with a clear invalid_input error instead of inventing a pour from zero or negative sizes.

How rectangular footing concrete volume is computed

On success the response echoes the rounded inputs, publishes volume_per_footing and total_volume (with volume as an alias of the total), plan_area_per_footing and plan_area_total for a quick sanity check against drawings, formula as the string V equals length times width times depth times count, message as a short English summary, and steps as an ordered array of substitution lines you can assert in tests or show to a client.

How to call the API and what comes back

Count must be a positive integer up to the published maximum; string forms of whole numbers are accepted when they match a strict finite numeric pattern, but fractional counts are rejected. Prefer sending numbers rather than pre-formatted strings when you control the client; when you must send strings, avoid currency symbols, unit suffixes, or thousand separators that would fail the finite-number pattern. Send a JSON body with four required fields: length (aliases footing_length, L, len, long), width (aliases footing_width, W, w, breadth), depth (aliases footing_depth, thickness, height, D, d, thick), and count (aliases quantity, n, qty, footings, num). Length, width, and depth must be finite positive numbers within the published absolute range so intermediate products remain finite in IEEE double precision on the Worker and in the browser. On success the response sets volume_per_footing to the rounded prism product, total_volume and volume to the product times count, plan_area fields to length times width (and times count), formula and message as described above, and steps as the substitution log. Failed validation—missing fields, non-finite numbers, non-positive dimensions, non-integer or non-positive count, or values outside absolute limits—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item and zero marginal unit price.

Practical tips, limits, and related searches

Measure length and width on the plan of the pad, and depth as the pour thickness from the bottom of the form to the top of the finished footing, using one consistent unit set. Keep dimensions inside the published absolute range so products cannot overflow into non-finite results the solver must reject. Prefer this capability when you already know the rectangular pad sizes and only need the pour volume; if your source is a continuous strip footing of constant section, you can still model segments as rectangles but must sum separate calls. If the engineer specifies a waste factor (for example five or ten percent), multiply total_volume yourself after the call; this tool intentionally returns the pure geometric volume so quotes stay transparent. When teaching or writing tests, pair a single-footing case (count equals one) with a multi-footing case that scales total_volume linearly, and include a deliberate zero depth or zero count to prove the invalid_input path. This landing targets people searching for a concrete footing calculator, footing volume, pad foundation concrete yardage, or length width depth count online; it is not a strip-footing trench estimator with variable width, not a slab-on-grade volume tool for whole floors, not a bag-of-concrete shopper that converts cubic metres to bag counts, and not a structural design check for soil bearing pressure. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when you deliberately send a zero width to verify error handling. Round-trip checks are easy: recompute length times width times depth by hand, multiply by count, and confirm the published total_volume matches within the same twelve-decimal rounding used for all numeric fields.