Name keychain size guide
that survives a pocket
A name keychain for your keys works best at 50 to 80 mm long, 15 to 25 mm tall and 4 to 6 mm thick, with a 4 to 6 mm ring hole for a standard 20 to 25 mm split ring. Bag tags can go up to about 110 mm. Below are the numbers per name length, material and ring.
By Philipp Baldauf · Updated September 29, 2026
The short answer
Typical sizes for a printed name keychain that goes on a key ring, measured on the finished print.
50 to 80 mm
Length
Including the ring. Longer tags catch on pocket seams and lever hard on the ring.
15 to 25 mm
Height
Keeps the letters at 10 mm or more, which is readable and prints cleanly with a 0.4 mm nozzle.
4 to 6 mm
Total thickness
Plate plus letters. Thinner flexes and cracks, thicker gets bulky next to a car key.
4 to 6 mm
Ring hole
Room for the 1.5 to 2.5 mm wire of a normal split ring to turn freely.
How the generator sizes a keychain
The name keychain generator builds the letters at a fixed size and puts a rounded plate behind them, with about 3 mm of padding and a ring on the left. There's no millimetre field in the editor. You set the final size by scaling the model in your slicer, which is quick and keeps the proportions right.
Three settings in the editor matter for size. Thickness sets how tall the letters are. Plate Padding (1 to 12 mm) sets how much plate sits around them. Ring Hole sets the hole as a percentage of the tag height, from 8 to 60%, so the hole scales along with the tag. Set all three before you download, because they're baked into the file.
Try your name
Keychain mode is on. Change the name and watch the plate grow with it.
Name length vs keychain length
What the file measures before scaling, computed from the font outlines at the generator's default size, ring included. The last column is the scale that brings a Baloo 2 tag to 70 mm.
| Name (letters) | Baloo 2, default size | Pacifico, default size | Baloo 2 scaled to 70 mm |
|---|---|---|---|
| Mia (3) | 66 x 29 mm | 95 x 37 mm | no scaling needed |
| Emma (4) | 104 x 28 mm | 118 x 37 mm | 67%, about 19 mm tall |
| Oliver (6) | 105 x 29 mm | 121 x 41 mm | 67%, about 19 mm tall |
| Charlotte (9) | 157 x 29 mm | 169 x 41 mm | 45%, about 13 mm tall |
| Maximilian (10) | 173 x 29 mm | 203 x 41 mm | 40%, about 12 mm tall |
Script fonts come out a few millimetres shorter after gap closing pulls the letters together. Letter width varies a lot: an m is three times as wide as an i, so count width, not letters.
Long names: go longer, not smaller
The table shows the catch. A nine-letter name squeezed to 70 mm ends up 13 mm tall, and the letters shrink to about 9 mm with strokes under a millimetre. That's at the edge of what a 0.4 mm nozzle draws cleanly. Our text size guide has the limits per nozzle.
For long names, let the tag grow to 90 to 110 mm and hang it on a bag instead of a key ring, or use a nickname. A condensed font helps too: Oswald and Anton fit more letters into the same length than Baloo 2 or Poppins. If you print a whole list with short and long names, the bulk keychain page shows how to keep them consistent.
Thickness for PLA and PETG
The plate is 2 mm deep and its top sits at 2.5 mm up to a thickness setting of 5 mm; above that it grows to 40% of the letter thickness. Values at 100% height.
| Thickness setting | Letters stand out | Total thickness | PLA | PETG |
|---|---|---|---|---|
| 2 mm | 1.5 mm | 4 mm | bag tags only | fine for keys |
| 3 mm | 2.5 mm | 5 mm | good for keys | the sweet spot |
| 4 mm | 3.5 mm | 6 mm | sturdy, next to car keys | very sturdy |
| 5 mm | 4.5 mm | 7 mm | chunky, kids' bags | chunky, kids' bags |
| 8 mm | 7.5 mm | 11.2 mm | too bulky for a pocket | too bulky for a pocket |
PLA is stiff and snaps when bent, so give it the extra millimetre. PETG bends a little and forgives more. TPU keychains can be as thin as 3 mm total because they never snap.
Ring hole for 20, 25 and 30 mm split rings
The Ring Hole slider is a percentage of the printed tag height. Pick the hole you want in mm, then read off the setting for your tag height.
| Ring | Typical wire | Hole that works | Setting at 20 mm tag height | Setting at 25 mm tag height |
|---|---|---|---|---|
| 20 mm split ring | 1.5 to 2 mm | 4 to 5 mm | 20 to 25% | 16 to 20% |
| 25 mm split ring | about 2 mm | 5 mm | 25% | 20% |
| 30 mm split ring | about 2.5 mm | 6 mm | 30% | 24% |
| Ball chain (2.4 mm balls) | 2.4 mm | 3.5 to 4 mm | 18 to 20% | 14 to 16% |
| Small carabiner | 4 to 5 mm | 7 mm | 35% | 28% |
Leave the slider untouched and the generator picks 28% of the tag height, with a floor of 6 mm at default size. Scaled to 67% for a 70 mm tag, that lands at about 5 mm, which fits a 20 or 25 mm ring. Check the wire of your rings with a calliper, they vary by brand.
Scale it in the slicer without losing strength
- 1
Turn off uniform scaling
In Bambu Studio, OrcaSlicer, PrusaSlicer and Cura there's a lock or a checkbox for uniform scaling. Turn it off.
- 2
Scale X and Y by the same percentage
Enter the same value for both, for example 67% for Emma at 70 mm. Leave Z at 100%. The plate and the ring stay 2.5 mm thick instead of shrinking to 1.7 mm.
- 3
Check the ring in the preview
Look at the wall around the hole. At default size it's at least 3 mm; at 67% it's about 2 mm, which is fine. Much below 2 mm, print the tag bigger or in PETG.
- 4
Print flat with walls, not infill
The file arrives lying flat, which is the strong direction. Use 4 or more wall loops so the ring and the letters print solid. The rest of the settings are in keychain slicer settings.
What breaks, and how to size against it
The ring wall
Most keychains fail where the split ring pulls. Keep at least 2 mm of material around the hole after scaling and use 4+ walls so that area is solid plastic.
A plate scaled too thin
Scaling uniformly to 50% turns the 2.5 mm plate into 1.25 mm, and it cracks in a pocket. Scale only X and Y.
Thin script strokes
Decorative scripts like Corinthia have hairlines well under a millimetre once scaled down. The letters stay on the plate, but the tips chip and print patchy. The cursive name keychain page lists which scripts hold up.
Heat
PLA softens from about 55 to 60 °C, and a car dashboard in summer gets hotter. Keys that live in a car want PETG.
Long tags on a key ring
A 120 mm tag on a key ring acts as a lever every time it swings. For long names, move to a bag or zipper, where there's less jerking.
What the size guide can't fix
The generator has no millimetre input, so you'll do one bit of arithmetic in the slicer. And because the letters come at one size, a long name either makes a long tag or a small font. There's no setting that makes Maximilian fit in 50 mm and stay readable. If you want two colours on top of the right size, the multicolour keychain guide has the layer to pause at. Designing is free; a download costs $4.99, or Unlimited from $9.99 a month (see pricing).
Questions people ask
What size should a 3D printed keychain be?
For a key ring, 50 to 80 mm long and 15 to 25 mm tall. That fits a pocket and keeps the letters at 10 mm or more. Bag and backpack tags can go up to about 110 mm.
How thick should a 3D printed keychain be?
4 to 6 mm in total, which is a thickness setting of 2 to 4 mm on the 2.5 mm plate. PETG is fine at 4 to 5 mm. PLA is stiffer and more likely to snap, so give it 5 to 6 mm.
What size hole does a keychain need?
4 to 5 mm for a 20 mm split ring, 5 mm for 25 mm and about 6 mm for 30 mm. The hole needs room for the wire to turn; a tight hole wears through. Keep at least 2 mm of plastic around it.
Does scaling in the slicer change the ring hole?
Yes, the hole scales with the tag. That's why the Ring Hole setting is a percentage of the tag height: work out the printed height, pick the hole in mm and set the percentage before you download.
How small can I make a name keychain?
A short name like Mia prints fine at about 45 mm long and 20 mm tall with a 0.4 mm nozzle. Once the tag drops under about 13 mm tall, the strokes get thinner than two nozzle widths and the letters look patchy. A 0.2 mm nozzle goes smaller, but prints much slower.
How much filament does a name keychain use?
A 70 mm keychain with a 5 mm total thickness uses about 4 to 7 grams, which is 10 to 20 cents of PLA or PETG. It prints in roughly 20 to 30 minutes on an A1 mini at 0.2 mm.