Measure the width of your desk and the width of your keyboard. Then pick a mat that's narrower than the desk but wide enough to hold the keyboard with comfortable room beside it for the mouse. With a full-size keyboard, that usually means a mat 80 or 90 cm wide, such as an XL at 80 x 40 cm or an XXL at 90 x 40 cm. With a compact keyboard or a small desk, an M at 70 x 30 cm is often enough.
That's the short answer. Below is a step-by-step way to get it right the first time, with the numbers side by side so you can compare.
Step 1: Measure your desk
Measure the desktop's width from edge to edge. Then measure its depth, from the front edge to the wall or to whatever stands at the back. Common desks are 100, 120, 140 or 160 cm wide (about 39, 47, 55 and 63 inches) and 60, 70 or 80 cm deep (about 24, 28 and 32 inches), but measure yours rather than guess.
Next, note what has to stay on the desk: a monitor stand, a lamp base, speakers, a laptop dock. A mat should lie flat, so anything with feet is best kept either fully on the mat or fully off it, never half on the edge where it can rock.
Step 2: Measure your keyboard
Your keyboard decides how much room is left for the mouse more than anything else. Typical widths:
- Full-size (with a number pad): about 44 to 46 cm (17 to 18 inches)
- Tenkeyless (TKL): about 36 cm (14 inches)
- 75%: about 32 cm
- 65%: about 31 cm
- 60%: about 29 cm (11.5 inches)
A keyboard is usually about 13 to 15 cm deep. Keep that in mind for Step 4, where depth comes in.
Step 3: Work out how much room your mouse needs
A mouse is about 12 cm long, but what counts is the space it travels. If you move it with small flicks of the wrist, a modest strip beside the keyboard is plenty. If you sweep with your whole arm, which is common when the mouse sensitivity is set low, give it as much width as your desk allows. It's also worth leaving a little space on the other side of the keyboard if you like a notebook there.
Here's how much room each mat width leaves beside the keyboard once the keyboard is on it:
| Mat width | Sizes | Full-size | TKL | 75% | 65% | 60% |
|---|---|---|---|---|---|---|
| 70 cm | M | 24 to 26 cm | 34 cm | 38 cm | 39 cm | 41 cm |
| 80 cm | Large, XL | 34 to 36 cm | 44 cm | 48 cm | 49 cm | 51 cm |
| 90 cm | L Extended, XXL | 44 to 46 cm | 54 cm | 58 cm | 59 cm | 61 cm |
| 100 cm | XXXL | 54 to 56 cm | 64 cm | 68 cm | 69 cm | 71 cm |
| 120 cm | Extreme | 74 to 76 cm | 84 cm | 88 cm | 89 cm | 91 cm |
The table tells you two things. First, a full-size keyboard on a 70 cm mat leaves the least room of any pairing, so if you keep your number pad, start looking at 80 cm and up. Second, a compact keyboard frees up a lot of width, so an M with a 60% board feels far roomier than the same mat with a full-size one.
Remember that the room in the table is the total. If you centre the keyboard under your screen, it's split between both sides. If you push the keyboard toward one end, it all goes to the mouse.
Step 4: Choose the depth: 30, 40 or 50 cm
Width gets the attention, but depth changes how a mat feels to use every day.
- 30 cm deep (M, Large, L Extended): holds the keyboard with space in front for your wrists and leaves more of the desk free behind it. A good fit for a shallow desk, or when your screen sits close.
- 40 cm deep (XL, XXL): room for the keyboard, your forearms resting at the front, and space to move the mouse up and down without running off the top edge.
- 50 cm deep (XXXL, Extreme): reaches far enough back that, depending on your desk, it can run under a monitor stand and turn the whole work area into one surface.
To check, lay a few sheets of paper on the desk at the mat's size, put your keyboard and mouse on them, and sit down. You'll quickly feel whether the back edge crowds your monitor or the front edge stops short of your wrists.
Step 5: Check it against your desk
A mat should fit within the desk. One that's a little narrower leaves a neat border of desk showing, and one that matches the width runs edge to edge. Here's how the widths fit the common desk sizes:
| Desk width | Mats that leave desk showing | Mat that runs edge to edge |
|---|---|---|
| 100 cm | S, M, Large, XL, L Extended, XXL | XXXL |
| 120 cm | Every size up to XXXL | Extreme |
| 140 or 160 cm | Every size, Extreme included | None |
One practical note: our mats are printed with dye-sublimation, which bonds the ink into the fabric using heat. Finished sizes can vary by 0.5 to 1 cm from heat shrinkage, so don't choose a mat to fill a gap to the exact centimetre.
Every desk mat size in one place
All the mats are 4 mm thick with stitched edges. Here are the sizes, with what each one suits:
| Size | Centimetres | Inches | Suits |
|---|---|---|---|
| S | 35 x 25 | 13.8 x 9.8 | A mouse on its own |
| M | 70 x 30 | 27.6 x 11.8 | Compact keyboards, smaller desks |
| Large | 80 x 30 | 31.5 x 11.8 | A full-size keyboard on a shallow desk |
| L Extended | 90 x 30 | 35.4 x 11.8 | Wide mouse sweeps where depth is tight |
| XL | 80 x 40 | 31.5 x 15.7 | A full-size keyboard with wrist room in front |
| XXL | 90 x 40 | 35.4 x 15.7 | A full-size keyboard and plenty of mouse room |
| XXXL | 100 x 50 | 39.4 x 19.7 | Covering the work area back toward the monitor |
| Extreme | 120 x 50 | 47.2 x 19.7 | Covering a desk 120 cm wide or more |
Quick picks for common setups
- Laptop and a mouse: an S if you just want a surface for the mouse, or an M if the laptop sits on the mat too.
- Compact keyboard on a small desk: an M leaves good mouse room without taking over the desk.
- Full-size keyboard for everyday work: an XL gives the number pad its space and your wrists a soft place to rest.
- Full-size keyboard and big arm movements: an XXL, or an L Extended if your desk is shallow.
- Everything on one surface: an XXXL, or an Extreme if your desk is 120 cm wide or more.
If you're torn between two sizes and the desk has room, the larger one is usually the safer choice. A mat that's slightly too big still works, but one that's too small means your mouse keeps running off the edge. You can browse every design across these sizes in our desk mats.
If you're printing your own picture
Size also changes the shape your picture has to fill. A 90 x 40 cm mat is long and narrow, and a 100 x 50 cm mat is a little taller for its width, so choose the size first and then crop the picture to fit. A picture prints sharp at about 150 pixels per inch of the mat's size or more. For an XXL, that's about 5,315 x 2,362 pixels. Lower resolutions print softer, which shows most on photos and small text. The upload guide marks a safe area 2.5 cm inside every edge, so keep faces, words and logos inside it, clear of the stitched edge.
Still not sure?
The desk mat size guide has every size laid out to compare. If your setup is unusual, send your desk and keyboard measurements to support@epicdesignpads.com. The team answers emails within 36 hours and can help you choose.