Tool

What will the steel weigh, and what will it cost?

A clear span frame at 120 ft and a 24 ft eave carries roughly 4.59 – 6.39 lb/sf of framing steel, which prices the building package near $16.22 – $20.72/sf. Change the inputs and watch which one is actually driving your number.

The case

7-22 values are strength-level, so the model uses the equivalent 2.5 psf on the 7-16 basis it is calibrated against. Why.

Baseline for comparison is a 20 ft eave, 25 ft bays, 20 psf ground snow, 115 mph wind, no crane.

Framing steel

4.59 – 6.39 lb/sf

Primary and secondary

Total steel

55 – 77 tons

Over 24,000 sf

Package

$16.22 – $20.72/sf

$389K – $497K

Installed

$25.13 – $39.37/sf

$603K – $945K

What is driving the weight

Each figure below is that input's effect relative to the baseline case, holding everything else fixed. The span sets the starting point; these move it.

Weight sensitivity at 120 ft of span
InputEffectWhy
Eave height 24 ft+7.2%A longer column raises the moment at the haunch, so the whole frame grows with the eave.
Bay spacing 25 ft+0.0%Wider bays mean fewer frames but deeper purlins and girts carrying more roof each.
Ground snow 4 psf-14.9%Gravity load straight into the rafters. On a wide building this is usually the governing case.
Wind 92 mph-10.4%Drives uplift and lateral demand, so it shows up in bracing and connections more than in the rafter.
Combined -18.0% Applied to the baseline weight for this span.

Cost moves less than weight: steel is roughly 55% of the package, with panels, trim, fasteners, and freight making up the rest.

At this span: Deep haunches and heavier anchor-bolt patterns. Foundation cost stops being a rounding error.

Planning-stage estimate calibrated to published industry ranges. Not a substitute for a stamped design by a licensed engineer.

Next step

Turn these numbers into real quotes

A dealer quoting from your actual geometry and load case beats any estimator, including this one. Three of them, each carrying engineer-stamped drawings for your state, cost you nothing to ask.

Get engineered quotes for a 120 × 200 × 24 ft building

Clear span reference table

The baseline the calculator starts from: a clear span rigid frame at a 20 ft eave, 25 ft bays, 20 psf ground snow, 115 mph wind, and no crane.

Framing steel and package cost by span, baseline case
Span Steel Package Installed What changes here
40 ft 2.20–3.20 $14–17 $22–32 Light frames. Span is rarely the cost driver at this width - eave height and snow load matter more.
50 ft 2.60–3.60 $14–18 $22–34 Still comfortably inside standard shipping and erection practice.
60 ft 3.00–4.20 $15–18 $23–34 The practical floor for commercial work. Below this width, small-building suppliers price better.
80 ft 3.80–5.20 $16–20 $25–38 The crossover band. Clear span and modular start to diverge in cost here - price both.
100 ft 4.60–6.40 $17–21 $26–40 Haunch depth begins to govern interior clearance. Check usable height, not just the eave.
120 ft 5.60–7.80 $18–23 $28–44 Deep haunches and heavier anchor-bolt patterns. Foundation cost stops being a rounding error.
150 ft 7.00–9.80 $20–26 $31–49 The practical ceiling for a standard single-span rigid frame. Past this you are buying custom engineering.
200 ft 9.50–13.50 $24–32 $37–61 Custom engineering, shipping splices, and heavier erection equipment. Modular usually wins on cost alone.
250 ft 12.50–17.50 $28–38 $43–72 Specialist territory. Justified by use, not economics - hangars, arenas, column-free process floors.
300 ft 16.00–23.00 $33–46 $51–87 The upper limit most manufacturers offer. Expect a bespoke frame design and a long lead time.

Steel in lb/sf; package and installed in $/sf of floor area. Installed includes foundation and erection and excludes interior buildout, insulation beyond a standard package, and site work. Planning-stage estimate calibrated to published industry ranges. Not a substitute for a stamped design by a licensed engineer.

Why weight rises faster than span

Double the span of a rigid frame and you do not double the steel — you roughly triple it. The bending moment at midspan grows with the square of the span, so a deeper section is needed; the deeper section is heavier, which increases the load it has to carry; and the taller haunch needs more material at the knee. Each effect compounds the last.

This is the entire reason the industry has frame types at all. A modular frame does not use cleverer steel than a clear span frame. It just refuses to let any single member span the full width, which steps back down the curve.

It is also why the cheapest lever on a wide building is almost never the steel spec. It is deciding that a column can stand somewhere. See the frame type selector for what that is worth at your width.

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