Collection 01
Glass & glazing calculators
Specifying glass comes down to four questions: is it thick enough for the load, how much does it weigh, how much heat does it let through, and what goes on the document you send the client. These tools answer them one at a time and hand their results to each other, with the standard cited and the arithmetic visible.
All of them run in your browser. Nothing is uploaded, nothing is stored, and none of them asks you to register.
How they fit together
One answer becomes the next question.
Most sites give you a calculator. This one gives you a route: the design pressure you work out on one page is the load the next page asks for, and the pane it sizes is the pane the third one weighs. No re-typing, and no wondering whether the three of you used the same number.
Wind pressure on a facade
Design pressure from basic wind speed, terrain, height and where the pane sits, to EN 1991-1-4 or ASCE 7. Hands the result straight to the thickness calculator — which is the input it asks you for.
vb 27 m/s · terrain II · zone A → 2.572 kN/m² design Structural · liveThickness & deflection under wind load
Checks bending stress and deflection for a rectangular pane supported on four edges. Monolithic and laminated, annealed through fully tempered, metric and imperial. Also gives you the thinnest standard glass that passes.
1200 × 2200 · 10 mm tempered → σ 9.96 · w 3.82 mm Handling · liveGlass weight
Weight of a pane, a laminated make-up or an insulating unit — total, per unit and per square metre — and what it means for getting it off the van and into the opening.
1200 × 2200 · 6 mm → 39.6 kg · 15.0 kg/m² · two people Thermal · liveU-value of an insulating glass unit
Centre-pane Ug to EN 673 for double and triple units — air, argon, krypton or xenon, with or without low-E. Splits every cavity into its radiation and gas parts, and tells you the best cavity width for that gas.
4-16-4-16-4 argon · two low-E → Ug 0.61 W/(m²·K) Safety critical · liveGlass balustrade
Stress and deflection of a free-standing barrier under a horizontal line load, at both interlayer bounds — plus the broken-ply check that most calculators quietly skip.
1100 mm · 0.74 kN/m · 12+12 → 16.3 mm, 96 % of h/65 Production · liveCutting optimiser
Nests your cutting list the way a table actually cuts — strips, guillotine snaps, edge trim and breakout width. Then it does what the free panel nesters get wrong: separates the scrap you bin from the offcut that goes back on the rack.
40 units on 4 sheets → 4.1 % scrap, 3.61 m² back on the rack Production · liveCutting plan
The shop-floor half of the optimiser. Every piece labelled on the diagram, the cuts listed in the order the table makes them with the measurement for each one, and each offcut with its real size so it goes back on the rack under a number instead of into the bin.
prints on A4, one page per sheet — no account, nothing uploaded Production · liveCutting labels
The job every shop does with a marker pen while the panes are still on the table. One label per pane, straight out of the solved nest and in the order the table cuts them: the same piece code as the plan, the size, the glass, which sheet it came off, and whether it was rotated.
plain A4 or 70 × 37 mm label sheets — 24 to a page, exact Reference · liveWeight and stock size reference
The handful of numbers that get looked up over and over: what glass weighs per square metre and per full sheet at every thickness, the standard float stock sizes, and the edge trim, breakout and minimum offcut that decide whether a list fits on three sheets or four. One page, made to be printed once and left in the van.
2.5 kg/m² per mm — a 6 mm DLF sheet is 108 kg Ordering · liveHow to measure an opening for glass
Measure the hole, not the pane in it: three widths, three heights, the smallest of each, and both diagonals. Then the deduction, which pulls against the edge cover the frame still has to keep. It matters because toughened glass cannot be trimmed — 4 mm oversize is a new pane and another week.
the measurement nobody takes: the diagonals Identification · liveWhy did this glass break?
Cracks branch away from the origin and never towards it, so following them backwards finds where it started — and what sits there is the answer. Impact, thermal stress, edge damage or a nickel sulphide inclusion, each with its own signature, and the argument about who pays usually turns on which one it is.
toughened with no strike mark is not automatically nickel sulphide Identification · liveMisted double glazing
The water sits on one of four surfaces and only one of them means the window has failed. Wipe it inside, wipe it outside: if neither reaches it, it is in the sealed cavity, the seal has gone and the desiccant is saturated. That unit is replaced whole.
condensation on the outside means it is insulating well Identification · liveIs this glass toughened or annealed?
Five checks in the order worth doing them: the permanent mark to EN 12150-1, the polarised-light test you can run with sunglasses on installed glass, what the edges and the roller wave tell you, what the pane's own history rules out, and the break pattern that is certain and destroys the evidence. Plus why a toughened pane sometimes breaks with nobody near it.
Spots that move when you tilt your head — toughened Identification · liveLow iron, or ordinary clear float?
Sight along the edge and ordinary float is green, low iron is not — but your eye adapts within seconds, so a single pane on its own is a guess. What to compare it against, the white paper test, why the green builds with thickness, and the jobs where it costs you an argument: white splashbacks, balustrade edges, glass floors and shopfronts.
Doubled light path — a white splashback comes out pale green Acoustics · liveWhy the two panes must not match
Every pane goes acoustically transparent at one frequency, and thickness decides which one. Two identical panes fail at the same place, so the unit gets one deep hole instead of two shallow ones — and making them different costs nothing. The coincidence dip, the mass-spring-mass resonance, what an acoustic laminate really does, and why Rw is the wrong number to compare when the window faces a road.
Rw 40 with Ctr −7 is worse against traffic than Rw 38 with −3 Production · liveOffcut inventory
The rack against your wall is glass you have already paid for. List it, and the optimiser cuts the next order out of it before it buys a sheet — but only opens a piece when doing so removes a whole sheet from the order, so good stock is not fragmented for nothing.
on one 40-piece job: 4 sheets down to 2, 398 € not spent Furniture · liveTable tops and shelves
How thick the glass needs to be for a top, a shelf or a screen — checking the spread load and the concentrated one, which is the check that actually decides and the one most guides skip.
800 mm shelf · 10 mm · 50 kg point → 19.6 N/mm² vs 7.1 spread Deliverable · liveSpecification sheet
Collect results from any of the tools above, add your logo and the project details, and print the branded PDF you send to the client. Still in your browser: nothing uploaded, no account.
your logo · your details · a real PDF · nothing uploaded