S type
Two half elbows in one plane, with or without an insert. Six ways in: angle, offset, overall length, 45°, insert, or offset X and Y together. Tap either elbow in the 3D view and its own calculator opens on that angle.
Pipefitter's calculator
XPipe Pro
Offsets, rolled elbows, cuts and layout — worked out to the millimetre and drawn to scale, on the pipe you are actually holding.
No ads. No tracking. No account. Everything works offline.
- 22calculators
- 21languages
- 10standards
- 100pipe sizes
- 152flanges
- 0ads
Closed test · Android
Get on the tester list
XPipe Pro is running as a closed test on Google Play. Google only shows the app to addresses that are already on the list, so send yours and you will get the opt-in link back.
- Send the Google account address you use on your phone.
- It goes on the tester list — usually the same day.
- You get a Play opt-in link back, and the app installs like any other.
Try the maths
Two half elbows, one offset
This is the app's own arithmetic, running here in the page. Change anything and the drawing and the figures follow.
Fitting angle
- Pipe to cut
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- Take-out per fitting
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- Overall length
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- Centre to centre
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With the fittings closed up this offset is the most the two radii can make.
What is inside
Twenty-two calculators, one reference frame
Rolled elbow
A 90° elbow turned about the inlet axis and a fitting that lays the run flat again. The pair buys height without moving the line sideways.
3D
A run across X, Y and Z. Both elbow angles are solved separately, because they differ — and the box you measure is drawn round the pipe, not round the theoretical corners. The headline figure is the insert between the two elbows — the pipe you actually cut.
Elbow cut
Cutting an elbow down to an odd angle: take-out, heel and throat arcs, chords, heights, and the arcs to mark back from the face you already have.
Forming gas
Purge time before the root pass, the gas it costs, and the inlet velocity that tells you the flow rate is wrong before the weld does.
Reducer cut
How far to cut a reducer back so its end comes out at the diameter you need — with the offcut and the cut plane drawn.
Cone layout
The sector to strike on flat sheet for a full or truncated cone, with the sheet it fits on, its area and what the finished part holds.
Square-to-round transitions
Twelve pieces off one construction: round over square or square over round, centred, offset on one axis or on both, with the square opening level or laid over — and a round pipe run down into a square or rectangular pyramid. Each returns the blank to cut, the true length from every corner out to its quarter of the circle, and the angle the sheet turns at each of those lines. The pyramid pair returns two patterns, because it is two jobs: the hole in the faces and the fishmouth on the pipe.
Pipe bank
Several lines making the same offset. Bend them all in one place and the spacing closes up on the slant; this says how far to hold each fitting back.
Segmented elbow
A bend built out of straight pipe. Every segment length, the angle to set the saw to, and the cosine wave to wrap round the tube to mark it out.
Branch / fishmouth
One pipe cut to sit on another, square or on the skew. The length to cut, the distance back from the face at 8, 16 or 24 stations round the girth, and the size, shape and position of the hole in the run. The deepest point of the cut changes formula as the branch lies down; the app knows where that happens.
Eccentric branch
The same joint with the two axes set apart, at any angle. Setting a branch across the run costs it its symmetry: the two horns stop matching, the deepest point of the cut wanders off the crotch, and the hole in the run needs both of its edges given at every station rather than one half-breadth. Each side is marked on its own, and an end view carries the centre distance — in elevation the offset lies along the line of sight and cannot be seen at all.
Elbow support
A tube cut to stand under a bend — the fishmouth again, with the run curved. The seat is a torus rather than a cylinder, so every figure comes off a different root: the length to cut, the ordinates round the girth, the height of the base plate, and the two angles at which the tube first touches the bend. Set it off to one side and the near and far horns stop matching, exactly as they do on an eccentric branch.
Falls
Per cent, mm per metre, one-in-something and degrees are four ways of writing one number. Type whichever the drawing used; the rest follow, with running levels down the line.
Volume and mass
The steel, what is in it, the lagging and the cladding — per metre for the hangers and in total for the crane. Plus the flooded weight, which is what a sling is really chosen against.
Pressure test
The gauge is down eight bar this morning: a leak, or a cold night? Water barely compresses, so a stiff system moves about 2.6 bar per degree. Whatever the cooling does not explain comes back in litres.
Thermal movement
ΔL for the actual grade, and the leg the movement needs. Held solid at both ends the stress is E·α·ΔT — over 400 N/mm² for stainless at 150 °C, and it does not depend on the length at all.
Cold spring
Cut the closing spool short, pull the ends together, weld. The run starts in tension and the nozzle sees half the reaction. The force it takes is worth reading first: thirty millimetres on a four-inch line is tonnes.
Weld preparation
V or J: the face width, the groove area and the filler a joint will take. On a heavy wall a J holds about half what a 60° V does, and the screen shows both so the saving is a number rather than a claim.
Weld shrinkage
One butt weld is a millimetre and nobody notices. Twenty on a rack run is two centimetres and the last spool does not reach. Work it out before cutting, and calibrate the figure on your own first spool.
Flange studs
Two flanges, a gasket, washers, nuts and the thread that has to show. ASME B16.5 gives the thickness without the raised face below Class 400 and with it above — read it the same way for both and every low-class stud is 3 mm short.
Support spacing
Three criteria at once: bending, sag, and — on a line that has to drain — whether the sag tilts the pipe back uphill faster than the gradient takes it down. The last one is not in the tables, and it is the one that catches hygienic work.
Flange tables
EN 1092-1, ASME B16.5 and the hygienic DIN 11853-2, drawn face-on beside the section — because the section gives you the thickness and the section alone never tells you where the holes go. Bolt circle, hole size, count and the chord between two neighbouring holes, which is how a pattern is checked with a calliper rather than a protractor.
Standards database
Searchable pipe tables with short, long and orbital elbow data, plus every standard the trade quotes and the fittings each one defines.
Isometric drawing
The symbol sheet: 127 marks from ISO 6412, ISO 4067, ISO 14617, ISO 10628, ISO 2553, ISA-5.1, ASME Y14.38 and ASME Y14.44 — every one drawn, named and explained in a line. Search matches the lettering inside a symbol too, so BW, PIC or =G1 finds itself. One button drops the partition between standards, which is what an unknown mark actually needs.
Bolt torque
Torque at the wrench, computed rather than copied off a table: stress area from the thread form, load from the grade and the share of yield you are pulling to, torque from the nut factor. The nut factor sits among the results with its own figure showing, because published values scatter by a third and everything downstream moves with it.
Level
The only screen that measures instead of calculating. Lay the phone along a pipe and read the fall that is already there, in degrees, per cent, millimetres per metre or one in something. Zero it on a surface you trust and the reading cancels both the phone's own case and the crown of the pipe.
On the phone
Every answer comes with a drawing
Not a diagram of something similar — a scale drawing of the exact assembly the numbers describe, dimensioned where a fitter would measure it.
Off the phone
The pattern does not have to stay on the screen
A development is only worth having if it reaches the metal. The segmented elbow, the branch, the cone and the whole square-to-round family hand theirs over two ways, both at full size.
DXF for the shop
The blank as a real CAD file, drawn 1:1 — R12, which every reader still opens, from a nesting table's software to a current CAD seat. Cut line, fold lines, setting-out, seam and lettering on separate layers, so a machine can be given the outline alone. Curves go out sampled far finer than the marking-out stations; a cone leaves as true arcs.
1:1 across A4
Not every site has an A3 plotter, and every site has A4. The same pattern is broken across A4 sheets at full size with a map sheet showing what goes where. Trim on the marked line, butt the sheets cross to cross, and stick the template straight onto the plate. Sheets that would come out blank are never printed, and every sheet carries a printed rule — measure it, and a printer that quietly scaled the page is caught in seconds.
Why you can cut to it
Two apps, one set of numbers
69 528
cases run through two independently written engines — one in Swift, one in Kotlin — on every change, and diffed figure by figure. Most come out identical to the last bit; nowhere do the two disagree by more than one part in a million million.
197
tests on the geometry itself: worked examples stepped off by hand, exact round trips of every inverse, and the identities that keep a drawing honest.
1 483
strings, translated in full into twenty-one languages. A half-finished language is kept out of the picker rather than shown as English patches.
Standards in the tables
- EN 10357 (DIN 11850 / 11852)
- EN 10374
- ISO 1127
- ISO 2037
- SMS 1145
- ASME B36.10M / B16.9
- DIN 11866-B
- ASME BPE (DIN 11866-C)
- EN 1092-1 (DIN 2501 / 2576 / 2633)
- ASME B16.5
- DIN 11853-2 / DIN 11864-2
Plus a library of every standard the trade quotes for pipe, fittings and joints — what each one covers, and the fittings it defines.
Built for the bench, not the office
Millimetres or inches, dark or light, twenty-one languages, and every figure readable at arm's length on a pipe rack.