How to Measure Baseboard (and Order Less!)

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This is a highly detailed (aka nerdy) post on how to measure baseboard so that you are able to order the minimum number of sticks, prevent measuring mistakes, and spend the least amount of time walking back and forth correcting long lengths of baseboard. This method also moves exact measuring towards the beginning of the project and a chunk of time fiddling with Excel or Google Sheets.

You’ve been warned…enjoy!

Tools required for this project

• Tape measure
• Pencil (not pen!)
• Paper
• Computer
• Your favorite spreadsheet application

Figure out which kind of baseboard you want.

This is the first decision for two reasons: thickness of the baseboard…

…and the length of each stick.

Baseboard can come in different lengths and the specific kind you choose may come in 8, 10, 12, 14 and/or 16 foot lengths.

For example, this prestained baseboard comes in 8, 12 and 16 foot lengths.

Tip: if this is a baseboard replacement project consider the height of the new versus the old baseboard. Specifically, what happens if you have builder grade basic 2.5 inch baseboard and replace it with a more impressive 4.5 inch baseboard?

The obvious answer: it is taller!

The better, and way more fun answer: you will have an easier time getting the old baseboard out–you can use your muscle as “needed” rather than carefully applied. Any incidental but totally necessary punches in the drywall from a pry bar will get covered up by the 4.5 inch baseboard. A total win!

Did you notice the baseboard here? Perhaps not. Admittedly, the paint job is pretty eye catching. You are more likely to notice a baseboard upgrade in the second photo.

Both baseboard thickness and overall stick length are both necessary for spot-on baseboard measurements. We’ll use these measurements in the next steps.

Measure out the entire house (or whatever rooms where you are installing the baseboard).

I drew a picture of the house and marked down the measurements on the respective walls. The back of an envelope will do. You can haphazardly draw the rooms as long as they are easily identifiable or labelled.

If this is a replacement project (as I did) you may or may not want to replace baseboard inside closets. For instance, I replaced the baseboard inside of the large bedroom closets and the kitchen pantry but I was unable to replace the baseboard in a small linen closet because the old baseboard was embedded in the tile.

Also consider if there are any other doors or window trim that could use a little extra eye candy. For example, the windows in my house were simple drywall boxes. When I installed the baseboard I also planned on fancify-ing each window with the same baseboard turned upside down along the bottom side.

KEEP ALL YOUR MEASUREMENTS IN INCHES. You’ll see why later.

This is the time to make sure you really get to know how much play your tape measure has at the “dumb end”. Normally it wiggles back and forth to account for the width of the tape measure metal lip. If there is more or less, this is the time to find out so you can account for it in your measurement. If you are of the mindset of keeping a tape measure at your current location where you are installing baseboard and another at the miter saw, make sure both have the same amount of wiggle room in the tip too.

Don’t worry about the additional length needed for outside corners or mistakes that will inevitably happen on an inside coped corner. We’ll revisit this in a couple steps. Just get your basic measurements.

While writing the measurements it is a good idea to keep a picture of the layout alongside:

1. A diagram makes our additional measurements for outside mitered corners and inside coped corners much easier in the next couple steps.
2. It is too easy to mix up sticks once cut, even if you are only doing one room.

Determine which method you want to use for your inside corners.

Figuring out the final length of baseboard requires a little more decision making than just the length of the wall. First, you have to decide if inside corners should be mitered 45 degrees or coped joints.

If you go for a mitered joint inside corner the measurement is simple–it is the length of the wall. But not so fast! Please don’t decide based on easy measuring. While the rest of this section is about the details of measuring a coped joint, it really is the superior method with better results!

For more on why you want a coped corner over a mitered corner check out this blog post: Choose Between Mitered and Coped Baseboard Inside Corners
For more on how to create a coped corner check out this blog post: How to Cope Baseboard Inside Corners

Enter all of your measurements into an Excel spreadsheet.

This is where it gets SUPER nerdy. After you write down all the measurements in Google Sheets, Excel or <insert your favorite spreadsheet application here>.

I used Google Sheets for this example. Unfortunately, fractions are not an easy measurement. Google Sheets does not know how to handle it other than assuming it is text. So I ended up breaking up the inches, numerator and denominator into separate columns. To make automating calculations easier across entire columns, I translated all of the fractions to a denominator of 16. Then I was able to calculate the decimal number–important for later.

Calculate extra lengths necessary to add to your original measurements.

If you opt for a coped corner, the next step is measuring the narrowest part of the baseboard you chose. You could make the overall measurement shorter by the thickness of the butted joint.

See, you don’t need to account for this part of the wall since it is filled in by the perpendicular piece of baseboard.

In my case, I can subtract 1/4 of an inch from any wall with a cope. Instead of running the miter saw all the way through the baseboard at a 45 degree angle, you cut it with the smallest point in your sights.

You can maximize baseboard by cutting a partial miter instead of a full one.

Depending on your level of comfort wielding a jigsaw free handed, you may or may not want to cut the board down to the full minimum pictured above. You can always cut more off, but you can’t once you cut it too short.

Nerdy tip: if you opt for coped corners, leave a little extra at the opposite end of each coped baseboard in case of mistakes. I’m not just saying a few inches. No. I think if you are still reading at this point, you are geeking out on fine tuning this measurement too. Let’s say our baseboard is 1/2 inch thick. Add another 11/16 of an inch at the opposite end of every coped corner stick in case of mistakes.

Here is why I’m throwing out those exact calculations:

If you create a proper cope on your first try you can back cut the opposite end at a 45 degree angle…

and then make a second cut at 90 degrees creating the butted end.

Remember that window sill tip? That first cut was my reward: a mitered end piece for the bottom of my window sills.

That little triangle you created from the overage of a first-time properly coped corner goes right on the end there. It creates a curved edge for your window trim instead of a abrupt butted end.

You see, the baseboard is half an inch thick and you also account an additional ⅛ inch for the blade.

Just to be clear, here is a diagram with the different measurements and placement of miter saw cuts all together. Note the dotted red line is where a third cut recreates the butted end and does not slice into the front of the baseboard.

Normally, a coped corner has a butted end on the opposite side. You go around the room with one coped corner on each wall of baseboard. So for every coped corner add in, for this example, another 5/8 of an inch to each measurement.

Tip: If you are an expert trim carpenter you may find it is easier to cope one end than the other. Word on the street is right handed carpenters go around a room with the coped end on the right and lefties keep it on the left end. I’m no expert trim carpenter and chances are if you are reading this blog you may not be either. However, I have artistic abilities which are easily transferable to projects like this, and, as you can see in this post, I love to optimize how I use materials. So if we do one room one direction and another room the opposite direction you end up with an equal number of little triangle ends for both sides of the window trim*. Love. It.

When it comes to outside corners you are definitely looking at a miter cut. This is another instance when you need to know the thickness of the baseboard because a miter cut is a hypotenuse of a 90 degree triangle. For example, 5/8” is the additional length needed for 1/2” thick baseboard.

Adjust your measurements as needed.

This is pretty much looking at your envelope and deciding which lengths need the additional length for coping inside corners and mitering outside corners.

First, 11/16” for coping and 5/8” for mitered outside corners.

Next up is automating adding this to the original measurements. First, you can calculate the new decimal number as well as adding the additional 11/16” and/or 5/8” to the original fraction numerator.

Now we need to put the fraction back together. It is easy enough to automate all of that too!

We know if the numerator is bigger than 15 we need to add another inch. So use the logical “if” condition =if(M2>15, C2+1, C2).

You can also automate calculating the final sixteenths of an inch using a similar logical calculation: =if(M2>15, M2-16, M2).

Now we have all our final measurements.

You could do this while you are measuring the rooms, but, knowing myself, I do not always remember the additional measurement. I also find it easier to do fractional math looking at the numbers, rather than on the fly in my head…at least I seem to get more consistent results that way (read–WAY less mistakes).

Assign each measurement to a stick of baseboard.

Now we are to the REALLY fun part: Tetris!

At this point you’ll want a new spreadsheet. Warning: since these are calculations you’ll need to copy them over to a new worksheet using the Paste Special function: Paste values only.

Start with the biggest measurements and start assigning them to different sticks.

Make sure to label which measurement goes with which wall on a room. By mixing measurements you could end up with any number of rooms assigned to each stick. Imagine blowing through all of your cuts on a stick within a couple minutes, surrounding yourself with an assortment of pieces and you have no idea where they go.

As you start getting down into the smaller measurements you start filling them into the remainder of the leftover pieces.

Of course, it’s not a simple as just plopping in the numbers–we’re automating this! As we move measurements around we can see what our running total per stick is by summing up what we have in a single column–on a per stick basis. We can also subtract the running total from the length of the stick to see what is left. Just keep adding measurements until it gets close to full.

Another consideration at this point is the different lengths offered for your chosen baseboard. I started off the example above using sixteen foot lengths. However, towards the end I had several long sticks that are very close to twelve feet. Jump on this if these two length options are available and the price is the same! Use whatever combination of different baseboard lengths maximizes your use.

You can see the baseboard measurements to the left are for sixteen foot sticks while the right are for twelve foot sticks.

However, there is still a catch–the miter saw blade takes 1/8 of an inch for every cut. So before you zero out your stick you’ll need to account for however many pieces you have assigned. For example, eight measurements means you’ll be making 7 cuts in between each stick (ignoring the last cut since it has no bearing on another piece). Depending on the number of cuts on any particular stick this could total up to a couple inches.

Remember how all our measurements are in inches? And why we chose Excel or Google Sheets? First, it is easy to cut and paste numbers back and forth, assigning measurements to different sticks of baseboard. Second, when you sum up the measurements in each column you know when you have hit the end of a full baseboard.

Extra credit: you can squeeze a little more out by trying to line up a coped corner with a mitered corner.

Final result:

Once you are done with assigning all measurements to each stick, print it out, order one or two extra, go to the store and pickup your order. Once home, set the load of baseboard next to the miter saw and start chopping! Even if you don’t get all scientific calculating the bare minimum you can slap a couple inches onto each measurement (round numbers are easy–no fractional math!), assign the measurements to sticks, and chop away.

Label each piece on the back after you cut it with the measurement and the room. You’ll still need your diagram to recall which end of the baseboard needs a miter and coping.

The beauty of this method is you can do all of that at once in your garage. Sure, the Google Sheet took a decent amount of time. However, you aren’t dodging self closing doors, knocking stuff off of a countertop, or navigating awkward turns in a hallway as you walk back and forth with a fourteen foot pole getting the measurement wrong.

A couple other issues to consider

*#1: Don’t cut off your hand or nick yourself with any of the wood cutting tools. You may have noticed in the spreadsheet above–none of the small pieces are coped. They might be mitered, but at that point cut the miter while it is still attached to the longer stick, leaving your fingers far, far away from the blade. If you forget and cut it straight, own up to the mistake and just re-cut it on your overage piece.

Oftentimes the small pieces dictate the direction of the cope. I’m not coping that small of a piece next to the door. So I’m forced into coping and mitering the much longer baseboard along the wall. Yes, I know it needs a paint touch up, but I’m not pulling paint out for this picture–this is a high traffic corner. 😉

#2: If your measurements of an entire wall are exact enough it could be too tight of a fit. If you can snap it into place so it fits like a pressure fitting, great. If it is too much subtract an eighth of an inch from the run so you’re not forcing a stick into place where there is a little bit of a bow. One sixteenth of an inch on either end is easily disguised with a bead of caulk. It is a fine line. On one hand you don’t want to be walking back and forth way too many times while you’re trimming little tiny pieces off an end whereas on the other end of the spectrum you don’t want to cut off too much and either have to recut the piece (you can still use it for other smaller pieces, but it is maddening at this point since you’ve already optimized them elsewhere) or fill in the gap with a lot of caulk.

An alternative solution, especially if you are dealing with textured walls, is to cut out part of the back corner.

#3: Remember more practice…and caulk (if your baseboards are painted)…are your friends if you are discouraged. Start with the closets first.

#4: This method of how to measure baseboard is more effective with larger projects. It also might be more maddening, but that’s the reason I went a little extra on automating the mathematical process. Fractional math is not my favorite. So by writing down the exact measurement I don’t have any mind games asking myself if I added in the cope or miter already. I also am less likely to mix up if I’m adding a cope or miter. It’s all on the worksheet!

#5: Don’t lose your envelope. Take a picture as soon as you’ve written all the numbers down. Then email it to yourself for safekeeping. Consider doing the same for the final Google Sheet.

We are maximizing the crap out of every stick when you learn how to measure baseboard with this method. In doing so, we essentially only need an extra stick just in case we make a bad cut. How much more you order is based on your comfort level. You certainly don’t want to be running back and forth to the store to get one more stick. If you order your materials and actually install them within the return window (no small feat if you are doing an entire house with a full time job and any kind of life) you could return your unused baseboard (per store policies).

Admittedly, some of this discussion is super detailed and nerdy. Your professional contractor will not be going to this level of detail at all since labor runs higher than the materials themselves. This is certainly a DIY way of measuring out baseboard. However, it also goes back to minimizing waste and how much you care. A finish carpenter installing baseboard everyday will have some of these tendencies based on experience–just not to the level of detail listed here.

After all this discussion you might lean towards a simpler kind of baseboard. Forget coping curves when you can butt joint a simple 1” x 6” (which is also a cope 😉 ).