Tank & vessel calculator
Works both ways: diameter and height from a required capacity, or capacity from dimensions you already have. Flat, ellipsoidal, torispherical, hemispherical and conical ends are all supported, and the volume of each head is added to the shell rather than ignored.
shell V = (π/4) D² H ellipsoidal head V = (π/6) D² × (D/4) ... per 2:1 head cone V = (π/12) D³ / tan(θ/2)
The vessel-type presets set proportions and head styles only. Capacity always comes from you, because process sizing depends on residence time and throughput rather than geometry — which is why there is a throughput × residence-time helper underneath.
It also gives a shell plate take-off: the straight side expressed as rings of stock plate. Heads are excluded from that count, because a dished or conical head is pressed from a blank rather than wrapped from plate.
MS & SS plate calculator
A ring — also called a shell course — is one horizontal band of plate, rolled to the curve and welded into a circle. The sheet’s width sets its height. The calculator plans those rings rather than dividing area by sheet size.
The planner is an unbounded knapsack over ring heights, worked in tenths of a millimetre so that exact means exact. It ranks candidate stacks by:
- fewest rings — every horizontal seam is a circumferential weld to set up, run and test, and that costs far more than the plate it saves;
- least trimmed off the top;
- least plate bought.
It will mix at most two stock widths. Mixing is how a plan lands on an awkward height exactly — 14 ft is one 4 ft ring under two 5 ft ones, with nothing trimmed — but a yard orders plate, not arithmetic, and four different sizes on one shell is a mistake waiting to be cut.
Tick off the sizes you can actually buy and the plan only considers those. Weights are gross (what you buy, including offcut) and net (the steel in the finished tank); use gross for costing and net for foundations and lifting.
Engineering unit converter
Force, pressure, torque, power, energy, flow, velocity, area, volume, angle, length, mass and temperature, with every unit in the family shown side by side rather than one at a time. Conversion factors are exact where an exact value exists — a pound-force is exactly 4.4482216152605 N — and the standard accepted value otherwise.
Length opens on feet, because that is the unit this work is quoted in on site. The reference column below the result keeps the metric ladder in its own order so you can read across it.
Image converter and image to PDF
Convert between JPEG, PNG and WebP, adjust quality, resize, or combine images into a single PDF with a page size and margin. Both run entirely in your browser: nothing is uploaded, nothing is stored, and they keep working with the network off.
Images are only ever scaled down, never enlarged — leave a size field empty to keep the original dimension.
A note on the PDF reports
Every calculator can write its result out as a PDF. Those are generated on your device too, with no toolkit and no font embedding, which keeps them small and quick. The trade-off is that they use the base-14 Helvetica character set, so currency symbols and non-Latin scripts cannot appear in them — money is written with its ISO code instead.