STEEL QUANTITY CALCULATOR

HOW THE CALCULATION WORKS

1. 1. Count the bars. Number of bars = (span ÷ spacing) + 1, taken in each direction. A 30 ft (9.14 m) run at 150 mm centres gives 61 bars.
2. 2. Total the length. Multiply the bar count by the cut length of each bar, including a small allowance for cover and end bends.
3. 3. Convert to weight. Unit weight per metre = d² ÷ 162. So 12 mm = 0.888 kg/m, 10 mm = 0.617 kg/m, 16 mm = 1.580 kg/m — the full list is on our TMT weight chart.
4. 4. Add laps and wastage. We add 5% for laps, chairs and offcuts, then round up to whole 12 m pieces because that is how bars are sold.

STEEL CALCULATION FAQs

How do you calculate steel quantity for a slab?

Count the bars in each direction — clear span divided by the bar spacing, plus one — multiply by the length of each bar to get total running metres, then multiply by the unit weight d²/162 kg per metre. Add a lap and wastage allowance of about 5% for the bars you actually have to buy.

How much steel is needed for a 1000 sq ft slab?

A typical 1000 sq ft residential RCC slab with 10 mm bars at 150 mm centres both ways works out to roughly 1.1 to 1.4 tonnes of TMT, depending on span, thickness and whether beams are included. Use the calculator above with your actual dimensions for a closer figure.

What is the formula for the weight of a TMT bar?

Weight in kg per metre = d² / 162, where d is the bar diameter in millimetres. A 12 mm bar is therefore 144/162 = 0.888 kg/m, so a standard 12 m piece weighs about 10.66 kg.

What bar spacing should I use in a residential slab?

Most single and double storey residential slabs in Odisha use 8 mm or 10 mm bars at 125–150 mm centres both ways. Always follow the spacing on your engineer's drawing — this calculator estimates quantity, it does not design the slab.

Can DB Steel Hub quote the calculated quantity?

Yes. Send the calculated bar list on WhatsApp or call +91 93375 78041 and we'll confirm today's Odisha rate for TATA Tiscon, JSW Neo, Jindal Panther or Rungta, along with delivery in Cuttack.