Rebar Calculator API
Reinforcement-steel (rebar) maths as an API, computed locally and deterministically. The area endpoint computes the cross-sectional area of a reinforcing bar, a = π/4·d², its mass per metre (a·7850/1e6, steel ρ = 7850 kg/m³), the total area and mass for a number of bars, and — given a required steel area — the number of bars needed and the area provided. The spacing endpoint lays out bars across a section: from the width, the cover, the bar diameter and either a centre-to-centre spacing or a bar count it returns the other, n = floor((width − 2·cover − d)/spacing) + 1, the total steel area and the area per metre of width. The ratio endpoint computes the reinforcement ratio ρ = As/(b·d) of a section from the steel area (or the bars) and the section width and effective depth, as a fraction and a percentage, the single number that governs whether a beam is under- or over-reinforced. Everything is computed locally and deterministically, so it is instant and private. Ideal for structural and site-engineering tools, reinforced-concrete detailing, bar-bending schedules and steel take-off, and civil-engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is rebar geometry and quantities; for concrete mix proportions use a concrete API.
api.oanor.com/rebar-api
