Convert a rebar takeoff or order weight in pounds to US short tons or metric tonnes — the two ton units are 10.2% apart
← Back to the calculatorTakeoff = 16 bars × 17.75 ft + 18 bars × 15.75 ft = 567.5 ft of #5. At 1.043 lb per foot that is 591.9 lb. Divide by 2,000 for a US short ton: 0.296. Divide by 2,204.6 for a metric tonne: 0.269. Order: 34 bars × 20 ft × 1.043 = 709.2 lb — 20% more than the takeoff, because each bar carries an off-cut.
Open the calculator for the bar counts and weight, or read the three steps below for the conversion.
The word ton covers two different units of mass. A US short ton is 2,000 lb and is the ton a US rebar yard quotes in. A metric tonne (t) is 1,000 kg = 2,204.62 lb and is the ton a metric supplier, a non-US engineer, or an export invoice quotes in. The two are 10.2% apart: the metric tonne is the heavier of the two by exactly 204.62 lb.
The 10.2% gap is not rounding error. On the 18 ft × 16 ft slab the takeoff is 591.9 lb. At a $700/ton price the quote is $207.17 in short tons and $187.93 in tonnes — a $19 swing on one slab, on one material, for the same piece of steel. A rebar tonnage calculator has to pick the right ton for the supplier it is feeding, or report both and let the user pick.
The split between the takeoff and the order is the other thing this page works through. The takeoff is the net steel in the structure (567.5 ft, 591.9 lb on the worked example). The order is the whole bars you actually buy (34 bars of 20 ft, 680 ft, 709.2 lb). The order is the number to hand the supplier, and it is always larger than the takeoff by the off-cut percentage. Everything below runs on the 18 ft × 16 ft slab in #5 bar at 12 in o.c. with 1.5 in cover.
First turn the bar layout into a total length, then a total weight. The layout on a slab grid is the same job the slab rebar page walks through: floor( clear / spacing ) + 1 bars in each direction, each bar as long as the slab dimension it runs. On the 18 ft × 16 ft slab the two counts come off the two different dimensions:
The 1.043 lb/ft is the nominal unit weight of a #5 bar — the conversion factor that turns a length in feet into a weight in pounds. Each bar size has its own number, and the table is short enough to keep on hand:
| Bar size | lb / ft | kg / m | Bar size | lb / ft | kg / m |
|---|---|---|---|---|---|
| #3 (10 mm) | 0.376 | 0.560 | #8 (25 mm) | 2.670 | 3.973 |
| #4 (13 mm) | 0.668 | 0.994 | #9 (29 mm) | 3.400 | 5.060 |
| #5 (16 mm) | 1.043 | 1.552 | #10 (32 mm) | 4.303 | 6.404 |
| #6 (19 mm) | 1.502 | 2.235 | #11 (36 mm) | 5.313 | 7.907 |
| #7 (22 mm) | 2.044 | 3.042 |
Swipe the table sideways for more columns →
Multiply feet by the lb/ft for the bar size on the drawing and you have the takeoff in pounds. The conversion to tons is the next step. The weight page runs the same multiplication for a single bar, a stock length, or a whole order.
Two divisions, one for each ton. Same takeoff (591.9 lb), two answers, and the two answers are not the same number:
The gap is mechanical: a metric tonne is 1.10231 short tons. Multiply the tonnes by 1.10231 to get short tons; multiply the short tons by 0.90718 to get tonnes. The two units are right answers to two different questions, and a tonnage calculator that only reports one of them is half a tool.
| Figure | Pounds | Short tons (US) | Tonnes (metric) | Cost @ $700/short | Cost @ $700/t |
|---|---|---|---|---|---|
| Takeoff (net) | 591.9 | 0.2960 | 0.2685 | $207.17 | $187.93 |
| Order, 20 ft stock | 709.2 | 0.3546 | 0.3217 | $248.22 | $225.19 |
| Gap (order − takeoff) | 117.3 | 0.0586 | 0.0532 | $41.05 | $37.26 |
Swipe the table sideways for more columns →
The cost column shows why the unit choice matters. At $700/ton the takeoff costs $207.17 in short tons and $187.93 in tonnes — the same piece of steel, $19 apart, because the tonne is the heavier unit. Always confirm which ton the supplier has on the quote before comparing two prices. The takeoff itself is the same in both columns; the division is the only thing that changes.
The reverse question is the one a buyer actually asks: we need 2 tons of #4 on 20 ft stock — how many bars is that? The conversion is the same lb/ft table, just arranged differently. One short ton is 2,000 lb; one short ton of #4 on 20 ft stock is 2,000 ÷ (0.668 × 20) = 149.7 bars, rounded down to 149 whole bars you can buy. One metric tonne is 2,204.6 lb; the same #4 on 20 ft stock is 2,204.6 ÷ (0.668 × 20) = 165.0 bars, 165 whole bars. 40 ft stock halves both counts, because each bar now carries twice the steel.
| Bar size | lb / ft | Bars / short ton (20 ft) | Bars / short ton (40 ft) | Bars / tonne (20 ft) | Bars / tonne (40 ft) |
|---|---|---|---|---|---|
| #3 | 0.376 | 265 | 132 | 293 | 146 |
| #4 | 0.668 | 149 | 74 | 165 | 82 |
| #5 | 1.043 | 95 | 47 | 105 | 52 |
| #6 | 1.502 | 66 | 33 | 73 | 36 |
| #7 | 2.044 | 48 | 24 | 53 | 26 |
| #8 | 2.670 | 37 | 18 | 41 | 20 |
Swipe the table sideways for more columns →
The bars-per-ton column is what a buyer uses to translate a tonnage into a purchase order, but the number the rebar yard actually delivers is the order tonnage, not the takeoff tonnage. Going back to the 18 ft × 16 ft slab, the order is 34 bars of 20 ft = 680 ft = 709.2 lb. In short tons that is 0.355; in tonnes it is 0.322. The takeoff was 0.296 / 0.269. The order is 20% heavier than the takeoff, and that 20% is the off-cut on 34 bars — the 4.25 ft scrap from each 15.75 ft piece and the 2.25 ft scrap from each 17.75 ft piece, summed.
The order tonnage is the tonnage to buy. The takeoff tonnage is the tonnage in the structure; the order tonnage is what leaves the yard. On the worked slab the order is 0.355 short tons against a takeoff of 0.296, a gap of 0.059 short tons that is the price of buying steel in fixed lengths. The estimator page runs the same off-cut analysis in pieces and feet, and the weight page takes a single bar, a stock length, or a whole order straight to pounds.
It depends on which ton. A US short ton is 2,000 lb, and a metric tonne (t) is 2,204.62 lb — 10.2% heavier. A "ton" of rebar is 2,000 lb in the US system and 2,204.62 lb in the metric system. A rebar tonnage calculator converts a takeoff or order weight in pounds to tons in the right unit: divide by 2,000 for short tons, or by 2,204.6 for tonnes.
Two steps, then a division. First multiply the total bar length in feet by the lb/ft for the bar size to get the takeoff weight in pounds. Then divide by 2,000 for US short tons or by 2,204.6 for metric tonnes. For the order, multiply the number of bars by the stock length and by lb/ft, then divide by the same ton factor. On the 18 ft × 16 ft slab the takeoff is 591.9 lb = 0.296 short tons = 0.269 tonnes; the order on 20 ft stock is 709.2 lb = 0.355 short tons = 0.322 tonnes.
149 bars of #4 in 20-ft stock per US short ton (149.7 exact, rounded down to whole bars you can buy). Per metric tonne it is 165 bars (165.0 exact). The exact count is ton_lb ÷ (lb_per_ft × stock_length): 2,000 ÷ (0.668 × 20) for short tons, 2,204.6 ÷ (0.668 × 20) for tonnes. On 40-ft stock the same ton holds half as many bars: 74 per short ton, 82 per tonne.
Compute the takeoff first, then the order, and order by the order tonnage. For an 18 ft × 16 ft slab in #5 bar at 12 in o.c. both ways with 1.5 in cover: takeoff 567.5 ft = 591.9 lb = 0.296 short tons = 0.269 tonnes; order 34 bars of 20 ft = 680 ft = 709.2 lb = 0.355 short tons = 0.322 tonnes. The order is the number to buy, because the takeoff ignores the off-cut on every bar.
No. A metric tonne (t) is 1,000 kg = 2,204.62 lb. A US short ton is 2,000 lb. A metric tonne is 10.2% heavier than a US short ton, so quoting a rebar price in dollars per tonne versus dollars per short ton changes the effective cost by 10.2%. On the worked example a $700/ton price comes out to $207.17 in short tons and $187.93 in tonnes — the same piece of steel, $19 apart, for picking the wrong ton.
Order by the order weight, which is bars × stock × lb_per_ft. The takeoff is the net length of steel in the structure and is always less than the order by the off-cut percentage. On the 18 ft × 16 ft slab the takeoff is 591.9 lb and the order is 709.2 lb — a 20% gap. If you order by the takeoff you will run short by exactly that off-cut on the last bar.
Two multiplications and a division. total_lb = total_feet × lb_per_ft (0.376 for #3, 0.668 for #4, 1.043 for #5, 1.502 for #6, 2.670 for #8). Then tons_short = total_lb ÷ 2,000; tons_metric = total_lb ÷ 2,204.6. The two values differ by 10.2% — pick the unit your supplier quotes in. The reverse direction (a tonnage target to a bar count) is bars = floor( ton_lb ÷ (lb_per_ft × stock_length) ).