Describe the problem. Get the right tool.
53 calculators, simulators and builders for the trades, students and professionals. Type what you need to solve — the right tool opens, often with your numbers already in.
Explore the tools
Who it's for
Trades
Material takeoffs, code checks, electrical and PLC tools — the number before you buy or cut.
29 tools · 11 courses
Students
Math from fractions to calculus, with solvers that show the steps and lessons you can play with.
10 tools · 9 courses
Professionals
Tools for finance, teaching, physics, math and art — built to explain, not just compute.
14 tools · 5 courses
Every tool
Grouped by area. Filter by who it's for, or by the tools with a 3D view.
Trades
Concrete & Masonry
- Concrete volume calculator3DSlab, round column or square column: enter the size and get the cubic yards to order, checked in 3D.
- Concrete for any shape3DShape the pour to your real measurements — drag or type the corners — and get the exact volume to order, in 3D.
- Tape measure calculatorFeet, inches and fractions to 1/64: add, subtract, multiply, split a length into equal parts or see how many pieces fit.
- Slope & grade meterLay your phone flat on the surface to read the grade — or type a rise and run by hand. Works for driveways, drains, ramps, and grading.
Carpentry & Framing
- Stair calculator3DEnter the floor-to-floor height and tread depth to get step count, riser height, angle and stringer length, code-checked in 3D.
- Rafter calculatorGive it the pitch and building span to get the common rafter length, overhang tail, stock length and plumb-cut angle.
- Wall framing takeoffCount studs and plates for a wall — corners, T-intersections and openings included — with every line of the count shown.
- Deck boards & joistsCount the deck order the way the yard sells it: joists, decking by stock length with the gap included, and screws.
- Joist & rafter span checkerSay what the member is, how far it spans and its spacing, and see which No. 2 lumber sizes the IRC span tables allow.
- Deck beam sizerEnter the joist span, beam material and post spacing, and see which 1, 2 or 3-ply beam the IRC allows (Tables R507.5).
Industrial Electrical
- Industrial electrical calculator3DThree industrial checks: 3-phase voltage drop, line current from kVA, and a motor's full-load amps with breaker and wire.
- Motor circuit designerPick the motor and get the full NEC Article 430 branch circuit, drawn as a one-line — tap any element to see the code path.
- Motor circuit troubleshooting trainerA three-wire starter with a hidden fault and a voltmeter: place your leads, work the panel, and name the fault.
Automation & PLC
- PLC signal scalingConvert between wire signal, raw ADC counts and engineering units — plus the slope and offset for your scaling block.
- Ladder logic simulatorThe classic plant-floor circuits running a real scan: pick one, flip the inputs, and watch power flow through the rungs.
- Ladder logic builderWire real devices into rungs — contacts, latches, timers, counters — and watch them run on a live scan. Share the link and your circuit arrives running.
- PLC troubleshooting trainerA machine with a hidden field fault and the ladder online: work the panel, compare what the PLC sees with the machine, and name it.
Industrial Robotics
Industrial Maintenance
- Pulley & gear ratioBelt or gears: enter driver and driven sizes and get the ratio, output speed, torque multiplication and belt length.
- Bolt torque calculatorFrom bolt grade and size to the wrench setting, dry or lubricated — SAE grades in ft·lb, ISO classes in N·m.
- Shaft alignment (rim & face)Enter your rim and face dial readings and three distances to get the shim change at each foot, graded against field tolerance.
Plumbing
- Drain slope calculatorPick the pipe and the run to get the code-minimum slope and the total fall as a fraction you can mark on the level.
- Water pressure & elevationEnter the pressure at the meter and the fixture height to see what pressure arrives, and when code requires a regulator.
- Drain pipe sizingCount the fixtures on the line and the type of run, and read the minimum drain size straight off the IPC dfu tables.
Students
Arithmetic & Fractions
Algebra I & II
Geometry
Professionals
Finance & Accounting
- Estimate & Invoice StudioEstimates and invoices with your logo, color and header style, discounts and deposits — updating live, ready to print or PDF.
- Loan amortization calculatorEnter the loan and see each payment split into principal and interest — and what the loan really costs by the end.
- Compound interest calculatorSet the rate, the years and an optional monthly contribution, and watch compound growth pull away from simple interest.
Teaching
- Worksheet generatorPick a topic, difficulty and count, and get a print-ready worksheet with its answer key — shareable by link.
- Grade calculatorEnter your weighted categories and the scores you have, and see your current grade and what you need on the rest to hit a target.
- Rubric builderBuild weighted criteria, pick a scale and score the work — and see what your scale really rewards. Prints as a clean scoring sheet.
Physics
- Projectile motion simulator3DSet launch speed, angle and height to get range, peak height and flight time from exact kinematics — then scrub along the arc.
- Vector field explorer3DPick one of seven classic fields, read its divergence and curl at any point, and ride a streamline through the flow.
- Pendulum lab3DSet the length, release angle and gravity, and compare the exact period with the small-angle formula from class.
Mathematics
Art
- Color theory explorerPick a color and see its harmonies as geometry on the color wheel, with exact RGB, HSL and hex values and a WCAG contrast check.
- Perspective explorerDrag a box or tilt the camera and see where its vanishing points really land — computed from true central projection, not drawn by eye.
- Golden ratio explorerWatch the golden rectangle build itself, divide a canvas at the golden section, and compare it honestly with the rule of thirds.
Featured tool
Concrete volume calculator
Slab, round column or square column: enter the size and get the cubic yards to order, checked in 3D.
Open Concrete volume calculatorAbout Tlamatini
Tlamatini is Nahuatl for “the one who knows things.” Every tool explains how it works and cites its sources, and the math runs right in your browser.
Questions or a bug? Write to hello@tlamatini.io.