Rebar Calculator

How the calculation works

Unit mass = π ÷ 4 × (diameter ÷ 1,000)² × 7,850 kg/m³. Allowed pieces = ceiling[required pieces × (1 + allowance ÷ 100)]. Cuts per stock bar = floor(stock length ÷ cut length). Stock bars = ceiling[allowed pieces ÷ cuts per bar].

A worked example

Twenty 3 m cuts of 12 mm bar need 60 m, approximately 53.27 kg. With 5% extra pieces, plan 21 cuts. Two cuts fit in each 6 m stock bar, so buy 11 bars (66 m, approximately 58.60 kg).

Assumptions & exclusions

One diameter and one identical cut length per calculation. Assumes steel density 7,850 kg/m³ and zero cutting loss. Exact fits need review for end trimming and cutting method. Stock length must fit at least one cut; this tool does not join shorter bars. Purchased surplus includes offcuts and unused stock. Nominal theoretical weight may differ from supplier weight.

Does this work out spacing, laps or seismic detailing?

No. Obtain a bar schedule from a qualified professional. Enter the final specified cut length. Do not use this estimate to select bar diameter, spacing, anchorage or load capacity.

What does the price include?

Only the estimated material quantity multiplied by your entered price. No live prices are supplied. Delivery, labour, accessories and any taxes not included in your supplier’s price are excluded. Blank prices leave cost uncalculated; zero is treated as an explicit ₱0 price.