Calculate reinforcement steel quantities, bar bending schedule, cutting lengths, lap lengths, and cost. Y8 to Y32 bars with African steel prices.
| Bar | Dia (mm) | Weight (kg/m) | Area (mm²) | Std Length | Lap (Tension 40d) | Lap (Comp 25d) |
|---|---|---|---|---|---|---|
| R6 | 6 | 0.222 | 28.3 | 12m | 240mm | 150mm |
| R8 | 8 | 0.395 | 50.3 | 12m | 320mm | 200mm |
| R10 | 10 | 0.617 | 78.5 | 12m | 400mm | 250mm |
| Y8 | 8 | 0.395 | 50.3 | 12m | 320mm | 200mm |
| Y10 | 10 | 0.617 | 78.5 | 12m | 400mm | 250mm |
| Y12 | 12 | 0.888 | 113.1 | 12m | 480mm | 300mm |
| Y16 | 16 | 1.579 | 201.1 | 12m | 640mm | 400mm |
| Y20 | 20 | 2.466 | 314.2 | 12m | 800mm | 500mm |
| Y25 | 25 | 3.854 | 490.9 | 12m | 1000mm | 625mm |
| Y32 | 32 | 6.313 | 804.2 | 12m | 1280mm | 800mm |
R = Mild steel (stirrups/links). Y = High yield deformed bar (main reinforcement). Standard bar length in Africa: 12m.
Every reinforced concrete structure in Africa needs accurately calculated steel reinforcement. Under-reinforcing leads to structural failure; over-reinforcing wastes money. This calculator helps engineers, quantity surveyors, and contractors determine exact bar quantities, weights, cutting lengths, and costs — all calibrated for the bar sizes and steel prices used across African construction.
African construction uses metric deformed bars (Y-bars) for main reinforcement: Y8, Y10, Y12, Y16, Y20, Y25, and Y32. Mild steel round bars (R-bars) — R6, R8, R10 — are used for stirrups, links, and distribution steel. The standard bar length across Africa is 12 metres, supplied by manufacturers like Ajaokuta Steel (Nigeria), Devki Steel (Kenya), ArcelorMittal (South Africa), and Sentuo Steel (Ghana).
The actual cutting length of a bar differs from its measured length due to bends and hooks. A standard 90-degree hook adds approximately 9d (9 times the bar diameter) to the length. Each 90-degree bend deducts 2d. These adjustments are critical for accurate steel ordering and site cutting — this calculator applies them automatically based on your specified bar shapes.
Where bars are joined (lapped), the overlap must be sufficient to transfer forces. In tension zones, the standard lap length is 40d (40 times the bar diameter). In compression zones, 25d is typical. For Y16 bars in tension, this means a 640mm overlap. Inadequate lapping is a common cause of structural failure in African buildings — always verify lap lengths with your structural engineer.
Reinforcement steel prices fluctuate significantly across Africa. In Nigeria, prices range from ₦650,000 to ₦750,000 per tonne (2024 prices). Kenya averages KSh 120,000-140,000 per tonne. South Africa ranges from R15,000-18,000. Ghana is approximately GHS 12,000-15,000. Always verify current prices with your supplier before ordering — steel is one of the most volatile construction materials.