This choice matters more than any waste percentage.
Room 1
0 if unused.
Advanced options
Clear finished opening.
Miters and copes consume a little stock.
For the botched cut. One is standard.
Needed over floating floors.
About 17 lf per side.
This baseboard calculator plans the cuts wall by wall and compares every stock length — because what decides how much trim you buy isn’t a waste percentage, it’s whether your walls happen to fit the sticks.
The short answer
Baseboard is perimeter minus door openings, then cut from fixed-length sticks. A 14 × 12 ft room with one door needs 49 linear feet.
But the stock length you choose changes the answer more than any waste percentage: at 14 ft you waste 14% with 2 joints mid-wall; at 16 ft you waste 31% with none.
On this page
How to use this baseboard calculator
Enter the room and the calculator plans the cuts, then shows every stock length side by side. Three modes:
- Rectangular room — length, width and door count
- Wall by wall — for irregular rooms, up to four runs
- Known perimeter — if you’ve already measured
The header toggle switches between baseboard, crown molding and chair rail — which matters because crown runs continuously past doorways while the other two stop at them.
Leave stock length on “compare all lengths” and the calculator recommends one, preferring no mid-wall joints and then least waste. The comparison table appears in the results either way.
Why a waste percentage doesn’t work here
Every other baseboard calculator does the same thing: perimeter, minus doors, plus 10%, divided by stock length. The 10% is meant to cover miter cuts and mistakes.
But trim isn’t consumed by a percentage. It’s consumed by whether each wall fits a stick. A 14 ft wall from a 16 ft stick leaves a 2 ft offcut that’s useless on any other wall in the room. A 14 ft wall from an 8 ft stick needs two pieces and a joint in the middle.
Here’s the same 14 × 12 ft room with one door — 49 linear feet to install — priced against every stock length:
| Stock | Sticks | You buy | Waste | Mid-wall joints |
|---|---|---|---|---|
| 8 ft | 7 | 56 lf | 14% | 4 |
| 10 ft | 6 | 60 lf | 22% | 3 |
| 12 ft | 5 | 60 lf | 22% | 3 |
| 14 ft | 4 | 56 lf | 14% | 2 |
| 16 ft | 4 | 64 lf | 31% | 0 |
Waste ranges from 14% to 31% on identical work — and the 10% figure everyone quotes doesn’t appear anywhere in that range. It isn’t a cushion; it’s a number that doesn’t describe what’s happening.
Look at the 14 ft and 16 ft rows. Both need four sticks. The 14 ft option costs 8 fewer linear feet, but puts two visible joints in the middle of walls. The 16 ft option costs more material and has none.
That’s the decision, and it should be a decision. Most calculators never surface it because a percentage can’t express “this length gives you a seam mid-wall.”
Choosing a stock length
| Stock | Good for | Cost |
|---|---|---|
| 8 ft | Small rooms, closets. Fits in a car. | More joints on any wall over 8 ft |
| 10 ft | Rooms with walls around 9–10 ft | Awkward for both small and large rooms |
| 12 ft | The common compromise | Wastes badly on 13–14 ft walls |
| 14 ft | Rooms with 13–14 ft walls | Not stocked everywhere |
| 16 ft | Long walls, jointless runs | Hard to transport; high waste in small rooms |
The rule finish carpenters use is simple: buy stock that covers your longest wall in one piece, and accept the offcut. A run without a seam looks better than a run with one, and no amount of glue and filler hides a scarf joint under raking light from a window.
Where that isn’t possible — walls over 16 ft — plan where the joint lands. Put it away from the main sightline into the room rather than accepting wherever the offcut falls.
A 16 ft wall won’t come from a 16 ft stick
This catches people out. A 16 foot stick of baseboard is nominally 16 feet, but you trim both ends square before fitting — the factory ends are rarely clean, and often slightly damaged from handling.
Allow the usual couple of inches for those cuts and your usable length is about 15 ft 10 in. A genuine 16 ft wall needs two pieces and a joint.
Some calculators add a cut allowance to each wall length, which implies you need a longer wall’s worth of material. That’s backwards. The wall is the length it is; what shrinks is the usable part of each stick.
The distinction only matters at the margin — but the margin is exactly where a 16 ft wall meets a 16 ft board, and that’s a common enough situation to get right.
The formula
1. Run = Perimeter − (door width × number of doors)
2. Usable stick = Stock length − trim allowance
3. Fit each wall to sticks, reusing offcuts where they reach
Perimeter = 2 × (Length + Width) · a standard door is 3 ft
Worked example — 14 × 12 ft room, one door, 16 ft stock
What gets deducted, and what doesn’t
| Trim type | Runs | Deduct doors? |
|---|---|---|
| Baseboard | Floor line, all walls | Yes — it stops at every opening |
| Base shoe / quarter round | On top of the floor, against the base | Yes — same run as baseboard |
| Chair rail | About a third up the wall | Yes — interrupted by door casings |
| Crown molding | Ceiling line | No — it runs continuously above doors |
A standard interior door is 3 ft wide. Measure wide openings, sliders and cased archways individually rather than assuming — a 6 ft slider deducts twice what a door does.
Don’t forget base shoe. Over a floating floor — laminate, LVP, engineered click-lock — the flooring needs an expansion gap at the wall, and base shoe is what covers it. It’s the same linear run as your baseboard, so order it together. And nail it to the floor, never to the baseboard, or you defeat the expansion gap you just covered.
Cope the inside corners, miter the outside ones
Rooms are never truly square. That single fact determines how corners are cut.
Inside corners
Cope them
One piece runs square into the corner. The second is scribed to its profile with a coping saw and slips over it. A coped joint closes tight even when the walls are a degree or two out, and stays closed as the wood moves.
Outside corners
Miter them
Two 45° cuts meeting at the corner. There’s nothing to cope against on an outside corner. Test-fit before nailing — you’ll often need a degree or two off 45 to close it.
Long walls
Scarf, don’t butt
Where two pieces meet mid-wall, overlap them with matching 45° cuts rather than butting square ends. A scarf joint stays closed as the wood shrinks; a butt joint opens into a visible gap.
A mitered inside corner is the classic beginner mistake. It looks fine in the shop and opens up the moment it goes on a wall that’s 89° rather than 90°.
Sticks by room size
One door deducted, trim loss allowed, stock chosen to avoid mid-wall joints where possible.
| Room | To install | Recommended stock | Sticks | Joints |
|---|---|---|---|---|
| 10 × 10 ft | 37 lf | 12 ft | 4 | 0 |
| 10 × 12 ft | 41 lf | 14 ft | 4 | 0 |
| 12 × 12 ft | 45 lf | 14 ft | 4 | 0 |
| 12 × 14 ft | 49 lf | 16 ft | 4 | 0 |
| 14 × 16 ft | 57 lf | 10 ft | 6 | 4 |
| 16 × 20 ft | 69 lf | 8 ft | 9 | 8 |
| 20 × 24 ft | 85 lf | 10 ft | 9 | 8 |
Notice the shift at 14 × 16. Once walls exceed the longest available stock, jointless runs become impossible and the calculator switches to minimising waste instead. In those rooms you’ll be planning joint positions regardless, so there’s no reason to pay for long stock.
Whole-house estimating
For budgeting a whole house before you’ve measured room by room, baseboard runs at roughly 0.30 linear feet per square foot of floor area.
| House size | Baseboard | 16 ft sticks |
|---|---|---|
| 1,500 ft² | ~450 lf | 31 |
| 2,000 ft² | ~600 lf | 42 |
| 2,500 ft² | ~750 lf | 52 |
Add door casing at about 17 lf per side, so 34 lf for a door cased on both faces. Window casing runs 18–22 lf each. A three-bedroom house typically comes to 600–700 lf of trim once everything is counted.
Treat this as a budgeting figure only. Layout dominates — a house with many small rooms, hallways and closets has far more baseboard per square foot than an open-plan one of the same area.
Baseboard height
| Ceiling | Baseboard height |
|---|---|
| 8 ft | 3¼ – 5¼ in |
| 9–10 ft | 5¼ – 7¼ in |
| Over 10 ft | 7¼ in and up |
The general principle is that taller ceilings take taller baseboard. Contemporary and farmhouse styles often go taller than the table suggests even at 8 ft, which reads as deliberate rather than wrong — but going shorter than the range makes a room look unfinished.
Note that taller profiles are less forgiving. A 7¼ in board shows every bow in the wall behind it, where a 3¼ in board flexes into line.
Baseboard estimating mistakes to avoid
- Adding 10% and calling it done. Real waste ranges 14–31% depending on stock length.
- Buying 16 ft stock for a small room. You’ll waste nearly a third of it.
- Assuming a 16 ft stick does a 16 ft wall. Trimming the ends leaves about 15 ft 10 in.
- Mitering inside corners. They open up on any wall that isn’t exactly square. Cope them.
- Butting pieces mid-wall. Use a scarf joint so shrinkage doesn’t open a gap.
- Deducting doors from crown molding. Crown runs continuously.
- Forgetting base shoe over floating floors. It covers the expansion gap.
- Nailing base shoe to the baseboard. Nail it to the floor, or the floor can’t move.
- Skipping primer on MDF. Cut ends drink paint and swell if left bare.
Frequently asked questions
How much baseboard do I need?
Add up the wall lengths and subtract about 3 ft per doorway. A 14 × 12 ft room with one door needs 49 linear feet. How many sticks that becomes depends on the stock length — at 16 ft it’s four sticks with no joints, at 8 ft it’s seven with four joints.
How much waste should I add for baseboard?
A percentage isn’t the right tool. Actual waste on a 14 × 12 room ranges from 14% with 14 ft stock to 31% with 16 ft stock, because it depends entirely on how your wall lengths divide into the sticks. Plan the cuts wall by wall instead, then add one spare stick for the botched cut.
What length baseboard should I buy?
Ideally one that covers your longest wall in a single piece, so there’s no seam mid-wall. That usually means 16 ft for rooms with walls over 14 ft. In small rooms long stock wastes heavily, so shorter sticks may be better value — the calculator compares all five lengths.
Can a 16 ft stick do a 16 ft wall?
No. You trim both factory ends square before fitting, which leaves about 15 ft 10 in usable. A genuine 16 ft wall needs two pieces and a scarf joint. It’s a small margin but a common situation, and worth knowing before you order.
Do I subtract doorways from baseboard?
Yes — baseboard stops at every door opening and cased archway. Subtract about 3 ft per standard interior door, and measure wide openings and sliders individually. Crown molding is the exception: it runs continuously above doors, so nothing is deducted.
Should I cope or miter inside corners?
Cope them. Rooms are never exactly square, and a 45° miter opens into a visible gap on a wall that’s off by a degree. A coped joint — one piece square into the corner, the other scribed to its profile — closes tight and stays closed as the wood moves. Outside corners get mitered, since there’s nothing to cope against.
How much baseboard for a whole house?
Roughly 0.30 linear feet per square foot of floor, so a 1,500 ft² house needs about 450 lf and a 2,500 ft² house about 750 lf. Add roughly 34 lf per door for casing on both sides. Treat it as budgeting only — layout matters more than area.
What size baseboard for 8 ft ceilings?
3¼ to 5¼ inches is standard. Nine and ten foot ceilings suit 5¼ to 7¼ inches. Taller profiles read as more traditional and are increasingly used even with 8 ft ceilings, but going shorter than the range makes a room look unfinished.
Do I need base shoe or quarter round?
Over a floating floor, yes — laminate, LVP and engineered click-lock all need an expansion gap at the wall, and base shoe covers it. Order the same linear run as your baseboard. Nail it to the floor rather than the baseboard, so the floor can still move.
How do I join baseboard on a long wall?
With a scarf joint — two matching 45° cuts overlapping, rather than square ends butted together. As the wood shrinks a butt joint opens into a visible gap, while a scarf joint stays closed because the overlap slides rather than parting. Land the joint over a stud so you can nail both pieces.
Is crown molding calculated the same way?
Almost — the difference is that crown runs continuously past doorways, so no openings are deducted. Crown also punishes mistakes harder: every cut is compound, and a mis-cut usually wastes the whole piece rather than a few inches. Buy longer stock and an extra stick.
MDF or solid wood baseboard?
MDF is cheaper, perfectly straight and takes paint well, but swells permanently if it gets wet and won’t hold a stained finish. Solid wood costs more, tolerates damp better and can be stained. If painting, MDF is the sensible default — just prime the cut ends, which absorb paint heavily.
Sources and method
- Cut planning uses first-fit decreasing bin packing across actual wall runs, with offcut reuse where a remnant reaches another wall
- Trim allowance is deducted from usable stock length rather than added to wall length, which is the physically correct treatment
- Stock lengths of 8, 10, 12, 14 and 16 ft reflect common US millwork availability; metric markets use 2.4 to 4.8 m
- Whole-house figure of 0.30 lf per ft² derived from published trim estimates and holds across the 1,500–2,500 ft² range
Related calculators
How this baseboard calculator works out its numbers
Each wall is treated as a separate run. Door openings are deducted from the wall they sit on, except for crown molding, which runs continuously. The trim allowance is subtracted from the stock length to give a usable stick, because trimming the factory ends shortens the board rather than lengthening the wall.
Runs are then packed into sticks using a first-fit decreasing algorithm — longest runs placed first, each subsequent run dropped into the first stick with room for it. That models what actually happens on site: you cut the long walls from full sticks and use the offcuts on shorter runs. Any wall longer than a usable stick is split, and each split is counted as a mid-wall joint.
The comparison table runs this for all five stock lengths. When set to recommend, the calculator prefers a length that produces no mid-wall joints, and among those picks the one with least waste. Where no jointless option exists — walls longer than 16 ft — it minimises waste instead, since joints are unavoidable.
These are quantities, not a cut list. The packing shows how many sticks the work needs, but which piece goes on which wall is a decision to make with the boards in front of you — grain, bow and any damaged lengths all affect it. Buy a spare stick regardless; one bad cut costs less than a second trip.