What Size Mitre Saw Do You Need for UK Skirting and Architrave?

The useful question isn't "what size mitre saw". It's "how wide is the widest thing I will cut, and which way up will it be lying when I cut it". Answer those two and the blade size falls out of them. Get them wrong and you'll own a saw that does architrave beautifully but can't reach across a skirting board. That's the most common mis-buy in this category.

It's a particularly British question, because UK trim comes in its own sizes. Skirting is sold in a fixed ladder of heights, with 144 or 145mm as the default. Architrave is 69 x 18mm unless somebody chose otherwise. Coving is a symmetrical cove that must not be cut lying flat. Those three facts, not the badge on the saw, decide whether you need a 210mm chop saw or a 255mm slide. Below, each job is sized against the crosscut figures (how wide a board the saw can cut across) that Evolution, DeWalt and Einhell publish for the saws in our top 7 mitre saws ranking.

The short answer

Start with UK trim sizes

UK skirting comes in a standard ladder of heights: 44, 58, 68, 94, 119, 144 or 145, 168 or 169, 194 and 219mm. It's 15, 18 or 25mm thick. If you have to guess without measuring, 144 or 145mm is the default in most UK homes and the safest single answer. The 94 to 119mm end is typical of new builds, and 194 to 219mm belongs to period property and barn conversions.

Architrave is simpler. 69 x 18mm is the standard, with 95 x 18mm as the wider option for taller rooms and heavier doors. One 4.4m length usually covers both legs of a door.

Those numbers map straight onto a saw's spec sheet, because a published capacity is written as width by depth. The width is how far the blade travels across the board. The depth is how thick the board can be. Skirting laid flat on the table is a piece 144mm wide and 18mm thick. Architrave laid flat is 69mm wide and 18mm thick. On trim, depth is never the problem. Width is the whole game.

210 and 216mm: the UK trim size

210 and 216mm blades are what UK shops are built around, and two completely different kinds of saw use that blade size.

A fixed head (a chop saw) only drops down into the wood, so how wide it can cut is limited by the size of the blade. Evolution quotes 125 x 55mm at 0 degrees on the R210CMS, and 85 x 55mm once the table swings to 45. Einhell quotes 120 x 55mm and 80 x 32mm on the TC-MS 2112.

Read those against the skirting ladder and the verdict is blunt: a fixed 210mm head is an architrave saw. It will mitre 69 x 18mm architrave all day with room to spare, and it'll take beading, stud work and 94mm skirting. But it can't reach across a 144mm skirting board lying flat at any angle, not even for a square cut. That isn't a criticism of the saws (both are well rated and cheap to own). It's a sizing fact people discover on the second day of a job.

A sliding head on the same blade is a different machine, because the head slides across the board as well as dropping. Evolution quotes 230 x 65mm at 0 degrees and 150 x 65mm at 45 degrees on the R210SMS+. DeWalt quotes a 250mm crosscut at 0 degrees on the DWS774-GB, on a 216 x 30mm blade turning at 4,500rpm.

That's the size where the standard UK skirting height becomes cuttable. It's why so many British second-fix chippies (the carpenters who fit the trim) run a 216mm slider rather than something bigger.

What swinging to 45 degrees costs you

Every spec sheet quotes its capacity at 0 degrees first. But that isn't the figure that matters for trim, because the corners on skirting and architrave are mitres. The geometry is simple. Swinging the table to 45 degrees multiplies the usable width by the cosine of 45, which is about 0.71. Evolution's own figures for the R255SMS-DB+ are exactly that: 300mm at 0 degrees becomes 212mm at 45. The others quote slightly less, which is a maker being cautious rather than a different rule.

So here's the working shortcut. It's our arithmetic from the published pairs, not something any maker prints: take about 70 per cent of the quoted 0 degree crosscut, and size to that. A saw that advertises 120mm gives you 80mm on a mitre. A saw that advertises 230mm gives you 150mm. Buy against the smaller number.

Where a cell says not published, it means exactly that. Those three makers don't print a 45 degree figure for those models. Borrowing one from a sibling model in the same range is how wrong numbers get into circulation: a figure for one model only tells you about that model.

254 and 255mm: what the bigger blade actually buys

A 254 or 255mm blade is usually sold as more power. For trim, it really buys two things: depth and mitre width. Evolution quotes 300 x 90mm at 0 degrees on the R255SMS-DB+, and 212 x 90mm at 45 degrees.

The 90mm of depth is the part a 210mm saw can't give you at any price: it's a 90 x 90mm newel post or fence post in a single pass. The 212mm at a mitre is what brings 169mm and 194mm skirting within reach, and period-property skirting is exactly where the smaller saws run out.

What it costs is weight. That saw is 18.3kg, against 12kg for the DeWalt and 5.8kg for the Evolution chop saw. That's the difference between a tool you carry upstairs one-handed and one that needs two hands and a stand waiting for it. If you work a room at a time in houses people are living in, that matters more than 60mm of extra capacity.

Flat on the table, or standing against the fence

This decides more purchases than blade size does, and it's the question most sizing guides skip.

Skirting can be cut two ways. Lying flat on the table, the board's height becomes the width the blade has to travel (144mm of crosscut for a 144mm board), and the corner is set on the mitre scale. Standing upright against the fence (the upright bar at the back of the table), the way it will sit on the wall, the blade only has to travel through 18mm of thickness. The board's height becomes a vertical measurement instead.

On bigger workshop machines, standing it up is the standard trick for tall skirting, and those saws publish a separate vertical capacity for it. None of the saws in this category do. Evolution, DeWalt and Einhell publish width and depth for boards lying flat, and nothing for a board stood against the fence, so there's no number here to size against.

The depth figures they do publish run from 32 to 90mm, which tells you the blade won't clear a 144mm board stood on edge on these machines. So in practice, on this size of saw in the UK, skirting is cut lying flat, and the 45 degree crosscut is the number to buy against. If you specifically want to cut upright, measure the fence height and the blade's reach on the actual saw before you commit, because it isn't on the spec sheet.

There's one honest workaround for a board slightly over capacity. Cut halfway, turn the board over with the same edge against the fence, and finish the cut from the other face. It works, and it's how a lot of 169mm skirting gets cut on a 210mm slider. But it costs accuracy: the two halves of the cut have to meet exactly, and on a mitre any misalignment shows on the face of the joint.

Coving is cut in position, not flat

Coving looks as if it should be the hardest cut on the job, and it's the easiest, as long as you don't lay it down. For a square corner, with any UK cove of any size and any brand, it's mitre 45 degrees, bevel 0: the table turned to 45, the blade upright. The piece is held in the saw at the angle it hangs on the wall.

That means the ceiling edge flat on the table, the wall edge flat against the fence, and the decorative face towards you: upside down and backwards from how it will hang. DeWalt describes the same position for crown moulding in its mitre saw manual. It's the whole reason a plastic coving mitre box works, and why the bevel scale never comes into it.

Plaster cove should never be cut lying flat. DeWalt's manual sets one condition for cutting mouldings flat: the moulding has to lie with its broad back surface down on the table. A cove has no broad flat back, just two narrow strips at its edges. Laid face up, it rests on two thin lines, rocks under the blade, and can't be held against the table and the fence the way the same manual requires.

Where coving does affect saw size is the fence. British Gypsum publishes the cove size for Gyproc Cove 100 and Cove 127, but not the spring angle (the angle it sits at) or the drop (how far it comes down the wall). A classic C profile is symmetrical, so the drop is the cove size divided by the square root of two. That's our arithmetic, not a published figure, and it puts Cove 100 at about 71mm down the wall and Cove 127 at about 90mm.

Nested in the saw, a Cove 127 therefore takes up roughly 90mm up the fence and 90mm across the table, plus any packer you slip behind it. Check that against your saw before you buy the coving, not after.

Timber and MDF crown moulding is the exception, because it does have a flat back and can be cut lying down. For a 45/45 spring angle at a square corner, that's a mitre of 35.26 degrees and a bevel of 30.00. DeWalt builds a fixed 30 degree bevel stop into the saw for exactly that cut, which confirms the number from the maker's side. There's no stop anywhere for 35.26, so you set it by eye between the 35 and 36 marks.

Single or double bevel on a long run

Bevel is the blade tilting away from upright. Mitre is the table turning. Whether you need the bevel to tilt both ways depends entirely on the last two sections.

• Coving nested in the saw, and skirting stood against the fence: the bevel stays at 0 all day. A single-bevel saw isn't a compromise here. It's simply enough.
• Skirting and crown cut flat: the corner is now set on the bevel scale, and a single-bevel head only tilts one way. Every corner going the other way means picking the length up, turning it end for end and re-marking it. And on a profiled board, like a torus or an ogee, turning it over puts the profile the wrong way up. Over a room, that's a lot of handling and a lot of chances to cut the wrong way.

Two saws in this category bevel both ways: the Evolution R255SMS-DB+ 255mm Double Bevel Sliding Mitre Saw and the Einhell TC-SM 2534/1 Dual 250mm Double Bevel Sliding Mitre Saw. The Einhell's listing gives 45 degrees of mitre and 47 degrees of bevel, each way, and it costs less than the Evolution.

Your corners aren't 90 degrees

Almost every sizing guide assumes a square room. British houses don't oblige. A Victorian or Edwardian terrace is routinely a degree or two out on every corner in the room, and not the same degree or two, either.

On any saw sold today, the setting is (180 minus the measured wall angle) divided by 2. An 87 degree corner needs 46.5 on each piece, and a 93 degree corner needs 43.5. The rule everyone repeats (measure the corner and halve it) is only right on the older kind of scale, which started at 90 and counted down. Every modern saw starts at 0 and runs both ways, so you subtract from 180 first.

Our free mitre and bevel angle calculator does that arithmetic for you. It also handles frames with any number of sides and coving at any spring angle, and prints an angle table you can take to the saw.

That has two consequences for sizing. First, out-of-square corners eat into the mitre range. So the 50 degree mitre swing on the Evolution sliders and the 50 degree quick release on the DeWalt are worth more in an old house than they look on paper. A bay window, for example, is a 135 degree corner and needs 22.5.

Second, how square the saw itself cuts matters more than its capacity for the look of the finished joint. A fence one degree out puts a degree into each half of the joint. 125mm multiplied by the tangent of 2 degrees is about 4mm of open mitre, and on 150mm skirting it's nearer 5mm. You'll see that from the doorway, on a saw of any size.

A related trick worth knowing: internal corners on skirting should be scribed, not mitred. Cut the first piece square into the corner. Then cut the second at the mitre angle, and follow the profile line with a coping saw so it sits over the face of the first. A scribed joint stays closed when the house moves, and it copes with an out-of-square corner without any adjustment.

It also quietly solves the capacity problem on tall skirting, because the first piece is only a square cut. A 219mm board needs 219mm at 0 degrees, which the 300mm and 340mm sliders here have, even though no saw in the category can mitre it flat. External corners are still mitred and glued.

So what size do you need?

Architrave, beading and trim only. A 210mm fixed head. The Evolution R210CMS 210mm Compound Mitre Saw has positive mitre stops (click-in presets) at 0, 15, 22.5, 30 and 45 degrees and weighs 5.8kg. Its supplied blade will cut mild steel and timber with nails in it, as well as plain wood. The Einhell TC-MS 2112 210mm Compound Mitre Saw is the volume seller. It runs at 1,600W and 5,000rpm on a 48-tooth blade that cuts cleaner in softwood and coated board, and it has more owner ratings than anything else in the category. Neither will reach across a 144mm skirting board.

Architrave plus standard 144 or 145mm skirting. A 210mm slide is the smallest saw that does it, and the Evolution R210SMS+ 210mm Sliding Mitre Saw is the one with a published figure to prove it: 150 x 65mm on a mitre. If the run is long enough that flipping boards is the slow part of the day, look at the Einhell TC-SM 2534/1 Dual 250mm Double Bevel Sliding Mitre Saw. It bevels both ways, has the widest published crosscut here at 340mm, and costs less than the other double-bevel saw. It's a bigger saw than this job needs, with a 250mm blade, so check you've got the bench for it.

Period skirting at 169mm or above, coving, posts, decking. The Evolution R255SMS-DB+ 255mm Double Bevel Sliding Mitre Saw, at 212 x 90mm on a mitre and 300 x 90mm square. It's the only saw here that publishes the depth for a 90 x 90mm post in one pass, and the only one that reaches 194mm skirting on a flat mitre. It's also 18.3kg.

Second fix, where repeatability beats capacity. The DeWalt DWS774-GB 216mm Sliding Compound Mitre Saw. Its XPS light casts the blade's own shadow across the work, so the line you see is exactly where it will cut, and unlike a laser there's nothing to calibrate. It has positive stops at 15, 22.5, 30 and 45, with a quick release to 50, and at 12kg it's a genuine one-hand carry up a stair.

No socket within reach. The Evolution R185CMS-Li 185mm Cordless Compound Mitre Saw, sold body only: there's no battery and no charger in the box, so it only makes sense if you already run Evolution's 18V EXT batteries. Evolution quotes a 105 x 45mm crosscut, which is architrave, beading and trim, and nothing wide.

219mm skirting. Scribe the internal corners, which are square cuts within the capacity of any of the sliders above. Take the external mitres to a bigger machine, a hand mitre box or a jig. Nothing in this category mitres a 219mm board lying flat.

One thing to check before you click buy on any of them. Every corded saw linked above is the 230 or 240V household version, which is what our ranking links to. UK building sites run 110V off a yellow transformer, and the same saws exist as separate 110V products. DeWalt adds -LX, so the site version of the DWS774-GB is the DWS774-LX, and Evolution and Einhell list their 110V models separately. They aren't interchangeable.

Read next

The full ranked shortlist, with the scoring rubric and the owner-rating evidence behind each pick, is our top 7 mitre saws buying guide. Before you cut anything, the mitre and bevel angle calculator turns a measured corner into a saw setting, and covers coving, frames and out-of-square walls. The rest of our free tools cover fixings, model numbers and battery platforms. How these rankings are put together, and the evidence behind them, is set out on how we rank. Current discounts across the catalogue are tracked on our tool deals page.