Fabrication Calculators
Free tools for U.S. industrial shops — press brake tonnage, CNC feed rate, sheet metal weight, roll forming output, machining cost, and motor sizing. No signup. No ads. Just the numbers.
The most thorough free motor sizing tool available. Enter HP or kW, voltage, PF, and efficiency — get NEC FLC per Table 430.250, minimum wire size AWG, max breaker size per NEC 430.52, overload relay setting, and a full voltage-drop check for any cable run. Covers 208V, 230V, 460V, 480V, and 575V systems.
How to Use These Fabrication Calculators
Every calculator on this page follows a Inputs → Formula → Code Reference → Action workflow. You enter your job parameters, the tool runs the engineering formula, surfaces the relevant code reference (NEC, AISC, or industry standard), and shows you exactly what to order, set, or buy.
The sequence below is the typical order of operations for quoting and setting up a new fabrication job — from raw material through electrical hookup.
1 Weight & Material
Start with the Sheet Metal Weight Calculator to confirm material weight for freight quotes, crane picks, and coil inventory planning. Supports all common alloys and gauges.
2 Bending & Forming
Run the Press Brake Tonnage Calculator before setting up a bend. Verify your machine can handle the job — tonnage overload is the #1 cause of tooling damage and frame fatigue.
3 Machining Speeds
Use the CNC Feed Rate Calculator to dial in RPM and IPM for your tool and material. Correct chip load extends tool life dramatically and improves surface finish.
4 Job Costing & ROI
Run the CNC Machining Cost Calculator before you quote. Then use the ROI Calculator to justify new equipment purchases with real payback numbers.
5 Roll Forming Output
The Roll Forming Estimator helps production planners schedule coil changes, downtime, and shift output targets for metal roofing and panel lines.
6 Electrical Hook-Up
Once the machine is on the floor, the 3-Phase Motor Sizing Calculator gives your electrician the exact wire AWG, breaker size, and overload relay setting per NEC 430.
All results from these tools are based on NEC Article 430, AISC standards, or published industry formulas. Use them for planning and pre-engineering, but always have a licensed electrician or P.E. verify final designs before installation. The tools are intentionally conservative — that's intentional, not a bug.
Shop the Tools These Calculators Size
Once you've run the numbers, you need the equipment on the floor. Below are the categories of gear our calculators are designed to size — searchable on Amazon with industrial-grade filters so you can compare options without sifting through consumer products.
* TWC Industrial participates in the Amazon Services LLC Associates Program. We earn a small commission on qualifying purchases — at no extra cost to you. We only link to product categories directly relevant to the calculations on this page. Full details in our affiliate disclosure.