Free 3D printing tools and calculators
Every time I helped my grandpa dial in his printer, I found myself reaching for the same spreadsheets and bookmarked forum posts. "What layer height works with my lead screw?" "How much is this print actually costing me?" "Why is my extruder under-extruding again?"
Since then, grandpa switched to a BambuLab printer and honestly... most of these problems just disappeared. Auto-calibration, input shaping, flow calibration built in. He doesn't need an E-steps calculator anymore because the machine handles it.
But I remember what it was like before. And I know a lot of people are still running Ender 3s, Prusas, Vorons, and other printers where you do have to tune things yourself. So I kept the tools around and polished them up. They're fast, free, no sign-up, and designed for people who'd rather be printing than doing math.
What's available right now
Here's the full lineup. Every tool is free to use, no account required.
Calibration and tuning
- E-Steps Calculator - Measure, calculate, and fix your extruder steps so filament flow is actually accurate. This is usually the first thing you should calibrate on a new printer (or after swapping an extruder).
- Flow Rate Calculator - Dial in your extrusion multiplier for walls and top layers that come out the right thickness. Run this after your E-steps are set.
- Layer Height Calculator - Find the "magic number" layer heights that match your stepper motor's native steps. Using these reduces Z-wobble artifacts and gives you cleaner layers.
- Volumetric Flow Calculator - Check whether your speed and layer settings will exceed your hotend's melting capacity. Handy when you're pushing print speeds and want to know the limit before you hear clicking.
- Stepper Motor Vref Calculator - Calculate the reference voltage for TMC2209, A4988, or DRV8825 drivers. Get it wrong and you'll either skip steps or cook your motor, so this one's worth getting right.
- Acceleration Distance Calculator - See how much distance your print head needs to reach full speed. Useful for understanding why small details print slower than you'd expect.
Filament and material
- Filament Spool Calculator - Weigh your spool, pick your brand from the database, and find out how much filament you actually have left. No more guessing and running out mid-print.
- Filament Density Converter - Convert between meters of filament and grams. Some slicers give you weight, some give you length, and you need the other one.
- Filament Drying Calculator - Look up the correct temperature and time for drying your filament. Covers PLA, PETG, ABS, TPU, Nylon, and others. Wet filament is the silent killer of print quality.
- Material Shrinkage Calculator - Calculate how much to scale up your model to compensate for shrinkage after cooling. Especially useful for ABS, Nylon, and PP where tolerances matter.
Cost estimation
- 3D Print Cost Calculator - Plug in filament weight, electricity, and machine wear to get the actual cost per print. I use this whenever someone asks me "can you print me one of those?"
- Resin Print Cost Calculator - Same idea but for resin. Accounts for resin usage, electricity, consumables like FEP film, and even failure rates.
Why I built these
I got tired of scattered calculators across random websites, half of which were broken or loaded with ads. I wanted something clean that just works, all in one place.
And since GrandpaCAD is all about making 3D printing more approachable, it felt like a natural addition. You don't need to be a GrandpaCAD user to benefit from these. They're just... there for everyone.
Request a tool
If there's a calculator or reference tool you keep wishing existed, I want to hear about it. Seriously. Just reach out through our contact page and I'll see what I can do.
The whole point is to make this collection actually useful for the people who use it. If something's missing, tell me.