Baseboard and Trim Calculator

Baseboard is measured in linear feet, not square feet, so the number you need is your room's perimeter with the doorways taken out. That part is easy. The part every calculator gets wrong is the step after it: you do not buy linear feet, you buy sticks, and the arithmetic for sticks is not the arithmetic for feet.

How to calculate baseboard linear feet

Three steps and one subtraction.

Measure the perimeter. For a rectangular room that is 2 × (length + width). A 12 by 14 room is 2 × (12 + 14) = 52 linear feet.
Subtract the door openings. Baseboard stops at a doorway. Two standard 3 foot doors take out 6 feet, leaving 46 linear feet. Check the actual openings rather than assuming, because standard door sizes run from 24 to 36 inches and a double or patio opening removes much more.
Do not subtract anything else. Baseboard runs behind a radiator, behind furniture, and across a closet doorway that has a threshold. The only thing that reliably removes baseboard is a cased opening with no wall under it.

Linear feet = perimeter − door openings

For a room that is not a simple rectangle, measure each wall separately and add them. The room calculator handles L-shapes and alcoves, and the wall calculator gives you the perimeter alongside the wall area if you are also painting. If you already have a square footage and a material width instead, the linear foot calculator converts between the two.

The part nobody calculates: sticks, not feet

Baseboard comes in fixed stock lengths, usually 8, 12, 14 and 16 feet. The tempting move is to divide: 46 linear feet ÷ 16 = 2.9, so buy 3 sticks.

That is wrong, and it is wrong by a whole stick.

A joint in the middle of a wall has to be a scarf cut, two pieces mitred at a shallow angle and glued so the seam does not open up. It is visible, it is the first thing to crack when the house moves, and finish carpenters avoid it whenever a single piece will reach. So each wall wants to come off one stick, which means you round up per wall, not across the job.

Our 12 by 14 room has four walls: 14, 12, 14, 12.

Stock length	Sticks needed	Total bought	Over the 46 ft needed
8 ft	2 + 2 + 2 + 2 = 8	64 ft	39%
12 ft	2 + 1 + 2 + 1 = 6	72 ft	57%
14 ft	1 + 1 + 1 + 1 = 4	56 ft	22%
16 ft	1 + 1 + 1 + 1 = 4	64 ft	39%

The 12 foot sticks are the worst option on the board, worse than the 8 footers, because a 14 foot wall needs two of them and you throw away 10 feet on every pair. The 14 foot sticks win outright. Nobody would guess that from dividing.

The general rule: match the stock length to your longest wall, not to your total. A stick a foot longer than the wall beats one a foot shorter by an enormous margin, and the second-longest wall matters almost as much. Run a few stock lengths through the calculator above before you order, because the cheapest stick is frequently the most expensive job.

Miter waste is per corner, not per foot

Every trim calculator tells you to add ten percent. That is a reasonable average and a poor model, because the waste does not come from the length. It comes from the cuts.

Each inside corner is coped or mitred and each outside corner is mitred, and every one of those cuts sacrifices a few inches while you fit it, plus the piece you ruin getting the angle right on an out-of-square wall. Call it half a foot per corner in practice. So:

Corners	Offcut	As a share of 46 linear feet
4, plain rectangle	2.0 ft	4.3%
8, one bump-out or chimney breast	4.0 ft	8.7%
12, an L-shape with a closet	6.0 ft	13.0%

Same wall length in all three rows. The waste percentage triples because the corner count triples, which is why a flat ten percent under-buys on a cut-up room and over-buys on a plain one. It is the same shape as the reason a small building loses a larger share of its floor to its own walls, covered in gross vs net square footage.

Count your corners, allow half a foot each, and add that to the net figure. Then round up to whole sticks, which usually absorbs it anyway.

Standard baseboard height

There is no code minimum. What exists is a set of stock heights and a proportion convention.

Off-the-shelf heights run 3.25, 4.25, 5.25, 6, 7 and 8 inches and up. A finish carpenter's guide to baseboard heights and proportions ties the choice to the ceiling:

Ceiling height	Baseboard that reads as proportional
8 ft	4.25 to 5.25 in
9 ft	5.25 to 7 in
10 ft and up	7 to 8 in, or built up with a cap

The same source offers a shortcut, that baseboard should land near one sixteenth of the ceiling height. Worth checking that against its own table before you lean on it:

Ceiling	1/16 of it	Recommended range	Verdict
8 ft (96 in)	6.0 in	4.25 to 5.25	overshoots
9 ft (108 in)	6.75 in	5.25 to 7	fits
10 ft (120 in)	7.5 in	7 to 8	fits

So the rule works for tall ceilings and runs high on a standard 8 foot one, which is probably why the two best-selling stock heights are 3.25 and 5.25 rather than 6. Use it as a ceiling on your choice rather than a target. Standard ceiling height covers what you are likely to be working with.

One more proportion worth knowing: the baseboard should not match the door casing width. The convention is base slightly shorter than the casing is wide, or noticeably taller if you are adding plinth blocks. A 3.25 inch casing pairs with a 5.25 inch base; a 4.5 inch fluted casing pairs with a 7 inch base and a plinth. Matching the two exactly is the giveaway of a parts-bin job.

What baseboard costs to install

Baseboard is priced per linear foot, and a hired quote is mostly labor. Rather than quote a range, here is where the number comes from.

The labor side. The Bureau of Labor Statistics puts the median carpenter wage at $29.12 an hour, or $60,580 a year, as of May 2025. That is the wage, not the rate you are billed. Load it for payroll tax, insurance, tools, vehicle, overhead and profit and a billed crew rate of $60 to $90 an hour is normal. A finish carpenter running plain base in an empty room covers something like 40 to 60 linear feet an hour including cuts, which puts labor at roughly:

Rate billed	40 lf/hr	50 lf/hr	60 lf/hr
$60/hr	$1.50/lf	$1.20/lf	$1.00/lf
$75/hr	$1.88/lf	$1.50/lf	$1.25/lf

The material side. Primed MDF base is the cheap end, primed finger-joint pine the middle, solid poplar or oak the top, and the price climbs steeply with height. Put your own figure into the calculator above rather than trusting a national average, because this is the one input you can check in ten seconds at a supplier's website.

What moves the labor number most is not the length, it is the conditions. Removing old base, patching behind it, scribing to an unlevel floor, painting in place, and working around furniture each add more than the trim itself. A quote for base in an empty new-build room and a quote for the same footage in an occupied 1920s house are different jobs at the same linear footage. The painting cost calculator decomposes a rate the same way if the trim is being painted too, and the paint calculator covers how little trim enamel a room actually takes.

Crown molding, casing, and quarter round

The perimeter math is identical for anything that runs along an edge. What changes is the subtraction and the waste.

Crown molding uses the full perimeter with nothing subtracted, because it runs above the doors. So the same 12 by 14 room needs 52 linear feet of crown, not 46. Crown also wastes more: the cuts are compound angles, the stock is more fragile, and a botched corner is a whole piece. Allow 15 percent rather than 10, and count corners the same way.

Door and window casing is measured per opening, not per room: two legs plus a head for each. A 3 by 6 foot 8 inch door takes about 2 × 6.9 + 3.3 = 17 linear feet with mitred corners.

Quarter round or shoe molding matches the baseboard run exactly, so it is the same 46 feet. It is a separate line item and a separate stick count, and it is what hides the gap when flooring goes in after the base.

Common mistakes

Dividing total feet by stock length. The single biggest error, and the reason for the table above. Round up per wall.

Buying the shortest sticks because they are cheapest per foot. A 12 foot stick in a room with 14 foot walls wastes more than an 8 footer. Match the stock to the longest wall.

Subtracting closets and alcoves. They add baseboard, they do not remove it. An alcove adds two returns and two more corners.

Using a flat waste percentage on a cut-up room. Corners drive the waste. Count them.

Forgetting the quarter round. If flooring is going in after the trim, you need shoe molding at the same linear footage, and it is easy to leave off the order.

Frequently asked questions

How do I calculate how much baseboard I need?

Take the room perimeter, which is 2 × (length + width) for a rectangle, and subtract the door openings. A 12 by 14 room with two 3 foot doors needs 52 − 6 = 46 linear feet. Then convert that to whole sticks by rounding up wall by wall, not by dividing the total.

How many sticks of baseboard should I buy?

Round up separately for each wall, because a joint in the middle of a wall needs a visible scarf cut. A 12 by 14 room needs four 14 foot sticks or four 16 foot sticks, but six 12 foot sticks, because each 14 foot wall would take two of them.

What is the standard baseboard height?

Stock heights are 3.25, 4.25, 5.25, 6, 7 and 8 inches. For an 8 foot ceiling, 4.25 to 5.25 inches reads as proportional; for a 9 foot ceiling, 5.25 to 7; for 10 feet and up, 7 to 8 or a built-up profile. There is no code requirement, only convention.

How much baseboard do I need for a 12x12 room?

The perimeter is 48 linear feet. Subtract the door openings, so one 3 foot door leaves 45 feet. In 12 foot stock that is four sticks, one per wall, with no cutting waste at all, because the stock length and the wall length are identical. You still buy 48 feet for 45 feet of run, and the 3 feet you do not use is the doorway.

Do I subtract doorways from baseboard?

Yes, the width of each door opening, because baseboard stops at the casing. Do not subtract closets, alcoves or windows: windows sit above the baseboard, and closets and alcoves add run rather than removing it.

How much waste should I add to a baseboard order?

Allow about half a foot per corner rather than a flat percentage. Four corners on a plain rectangle is about 4 percent of a 46 foot run; twelve corners on a cut-up room is 13 percent. Rounding up to whole sticks usually absorbs it.

How much does it cost to install baseboard?

It is priced per linear foot and mostly labor. At a billed crew rate of $60 to $90 an hour and 40 to 60 linear feet an hour, labor runs roughly $1.00 to $1.90 a foot, plus material. Removing old trim, scribing to an unlevel floor, and working around furniture add more than the trim itself.

Is crown molding calculated the same way as baseboard?

Almost. Crown uses the full perimeter with nothing subtracted, since it runs above the doors, so a 12 by 14 room needs 52 linear feet rather than 46. Add 15 percent rather than 10, because compound miters waste more and a bad corner ruins a whole piece.

Related tools and guides

Baseboard and Trim Calculator