Footing concrete volume calculator

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

How continuous strip footing concrete volume and bags are computed

To estimate bagged premix, divide volume by bag_volume (the yield of one bag in matching cubic units) to get bags_exact, then take the ceiling so you never under-order by a fraction of a bag. When bag_volume is omitted the calculator uses a documented default of zero point zero one five cubic units, which matches a typical roughly twenty-five kilogram bag in cubic metres when your dimensions are in metres; if you work in feet, pass an imperial bag yield such as zero point six cubic feet for a common eighty-pound bag. On success the response echoes the rounded inputs, publishes plan_area as length times width, volume as the prism product, bag_volume and bag_volume_defaulted, bags_exact and integer bags, spare_volume as the extra yield from rounding up, formula and unit_note strings, 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

String forms of numbers are accepted when they match a strict finite numeric pattern. 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 three required fields and one optional field: length (aliases footing_length, L, len, long, run), width (aliases footing_width, W, w, breadth, trench_width), depth (aliases footing_depth, thickness, height, D, d, thick, pour_depth), and optional bag_volume (aliases bag_yield, yield_per_bag, bag_size). 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. Bag_volume, when provided, must likewise be a finite positive number; when omitted the default zero point zero one five is applied and bag_volume_defaulted is true. On success the response sets plan_area, volume, bag fields, bags as a whole integer purchase count, spare_volume, formula as the string V equals length times width times depth with bags equals ceil of V over bag_volume, unit_note reminding you to keep one unit system, message as described above, and steps as the substitution log. Failed validation—missing fields, non-finite numbers, non-positive dimensions, non-positive bag_volume, 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. Pair this endpoint with your own waste multiplier after the call if the engineer specifies five or ten percent extra; the tool intentionally returns pure geometry and a transparent bag ceil so quotes stay auditable.

Practical tips, limits, and related searches

When teaching or writing tests, pair a metric case that uses the default bag yield with an imperial case that overrides bag_volume, and include a deliberate zero depth or zero width to prove the invalid_input path. This landing targets people searching for a footing concrete volume calculator, strip footing volume, continuous footing pour, or length width depth bags online; it is not a multi-pad isolated footing tool that multiplies by a footing count, not a full-slab on-grade estimator for rooms or garages, not a soil excavation bulkage calculator, and not a structural design check for soil bearing pressure or rebar schedule. 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, divide by bag_volume, ceil to whole bags, and confirm the published volume and bags match within the same twelve-decimal rounding used for all numeric fields.