Convert floor plan to actual ft X ft real world dimensions

Here is the floor plan of a house. The scale says “1/4” = 1’0"

I don’t have the original paper document so how do I know what 1/4" looks like. I opened the jpg in Photoshop and looked at the ruler. Was that a good thing to do? Can someone help me (or preferably, do it) come up with the dimensions in feet for each room? I’m comparing it with another residence (for furniture moving purposes, etc.).

There is a sad backstory, which I may tell in another thread if I can make myself do it later. Too sad and stressed at the moment.

There could be a pan of cashew fudge in it for you. Reviving an old tradition.

The bathtub/shower opening will probably be 5 feet long. You can get some idea of the scale measuring that with the Photoshop ruler. I don’t know anything about Photoshop, maybe you can change the scale on it’s ruler.

ETA: A 60" bathtub opening looks to be twice as wide as the smaller stove outline in the kitchen which would usually be 30". Of course it could be 32" and a 64" bathtub but those dimensions might be close enough for your needs.

That should work if the jpeg is full size to the given scale. But I don’t know how you would know if it is unless you already know how big one of the rooms is, or how big the house is in total.

This is pretty easy once you get a few braintwisters down pat…
The 1/4"=1’-0" on the plan is for when one is looking at a printed version (printed at 100% of the original size, of course!). Then, every 1/4" on the paper represents 1’-0" in the real world. That’s really all there is to architectural scale.
Yet you have a file that is really scaleless or a printout that may not be at 100? of the original, and in all likelihood, no way to know. And, as TriPolar points out, the only thing we might even have as a reference point is a bathtub which may or may not be 60" (5’-0") in length. Probably, but not certainly, and that’s a pretty short reference point for a whole floor plan.
But fear not. There are two things to do: ask whoever provided the original plan for at least one known dimension, or be OK working from the bathtub. Since you’re doing general furniture planning, the ‘horseshoes and hand grenades’ rule applies, and you’ll likely get actual measurements once you get in there anyway.
So, for now, in Photoshop, here’s the step by step:

  1. Select the bathub (or the other know dimensioned object) using the rectangular selection tool.
  2. Copy it, then hit file>new. Look at the inches dimension it gives you for the new file. For ease, I’ll say that it is 2.3 inches wide @ 72dpi.
  3. Now we know that a 5’ long bathtub is 2.3" inches in your file, and it should be 1.25" inches at the actual scale of 1/4"=1’-0". That’s 5 bathtub reference dimension feet, each a 1/4" long, so 1.25" overall at proper scale.
  4. A bit of math tells us that you’d need to reduce the original plan by 54.347% to get to 1/4" scale. I got there by dividing 1.25 by 2.3; you’d use your numbers, of course.
  5. Now, back in PS, look at your actual image size (the whole plan), multiply that width dimension by your scale factor (the 54.347 in my example), and then enter that revised number in the image size > width box. Deselecting ‘resize’ helps since you won’t lose resolution. Hit OK.

Now you should have your plan file at 1/4"=1’-0" in the document itself, ready for proper printing!

I suggest making the whole plan at the right scale - or whatever scale you want or fits on your paper - because it’ll make scaling your furniture pieces a lot easier.

If you’re ambitious, you can also likely find every piece of furniture you own in a SketchUp library. Import it into SU, then look at it in plan view (no perspective). Print them all at 1/4"=1’-0" and Bob’s your uncle. Having realistic looking furniture is a huge help, esp. for folks who may not be familiar with reading plans!

I would cross check the bathtub length by applying the scale to the doors. Interior doors are usually 32 inches but might be 30 or 36. Once you have a reference dimension for the tub, see how the derived scale applies to the doors. If it gives you a nice even width, you’re good. But if you get 21 or 39 or something, you know the reference dimension is off.

Thank you so much!

I’m too stressed from the general situation to actually follow your directions at this moment. I think I will be able to do it tomorrow morning. Brain not functioning well at the moment.

Thanks, y’all!

It looks like doors are usually between 32 and 36 inches wide, so you might use that as a sanity check on the bath tub size, assumption.

The entry door, from the front porch, would probably be 36".

ETA: Beaten to it! Went to lunch and still had the message mostly typed out already…

I would assume the doors are 36" since that seems to be standard for appliances. As near as I can tell that makes the front porch 52’ and change. From that dimension you ought to be able to work out the rest.

I’ll second that idea - front door is 36", interior doors are 32". Tubs typically are 60". While you’re doing renovations, knock out the wall between the hall and the living room (what a weird layout!)

So print it out, take the measurement of the front door on the print-out, and divide by 3 to get scale for 1 foot. (or tub/5)

The other thing to look at is the pixel size of the image. There is a good chance it was created using one of a range of standard pixel resolution to rendering sizes.
You will often see images at 72 pixels per inch. If the back of the envelope numbers suggested above come in close you can be pretty confident the actual value is one of the well known ones.
72 and 100, and multiples thereof.

I appreciate y’all’s helpful and practical answers. This may turn out to be moot (or mute, if you prefer :zipper_mouth_face:), as it looks like this floor plan is no longer part of my future.

I also thought this felt like a strange layout.

This is a 1920 Craftsman house and to me the layout is absolutely perfect. I guess ya gotta see it in person. That piece of wall that @md-2000 wants to knock out holds the wall heater (no longer functional but still in place). The hallway itself functioned as ductwork to move the heat into the rooms that open into it. The living room has a fireplace. On the living room side, there are bookshelves up against that section of wall.

If this is a standard design like a Craftsman pre-fab, then it’s probably possible to find the exact dimensions online elsewhere.

Well, as I mentioned in the my other thread about executors, I’m going to be moving. Sadly.

Great job explaining this. Kudos.

Years ago my gf asked me to measure our living room, dining room, and master bedroom. I grabbed my tape measure and a notepad and boom, I was able to supply her with numbers.

She then used the numbers I’d supplied and came back to me telling me I’d screwed up. I remeasured, wrote down what I got. Again, she told me I screwed up.

She went through her files and found the original floor-plans. I sat down with them and calculated the room’s measurements. This time when she told me I was wrong again, I asked her what she was doing. Turns out she was going to re-carpet those rooms. I was giving her measurements in feet and inches which she was multiplying to get square feet. Carpet, it turns out, is sold by the square yard. She kept getting $$$ that was way too expensive.

Different strokes, etc. Having to go through the study or dining room to get to the rest of the house just seems odd to me. I guess it depends if the front door is for decoration or for regular use. I once lived in an area of northern Canada for a few years, where the front doors often opened into the living room - southern suburban design. In winter, rather than flood the livingroom with subzero air, most people piled insulation between the front door and screen door and excusively used the back door. Most of the older houses where I grew up had a vestibule, even in relatively mild Toronto, to prevent chilling the house.

This.

The part I found most odd is that there’s an exterior door in the master (and only) bedroom. Good in case of a fire, I suppose, but how often is that going to be used?

That is a feature often found in houses of this vintage. I looked at another house today that has one. I’ve heard it called “the gentleman’s door.” I’m guessing the purpose is so that the gentleman can come and go discreetly and not rouse the whole household. All of the houses in this neighborhood also have maid’s quarters in the back. A maid might have been expected to open/answer the front door at any time.

Many of the things I love about this house are features that don’t make sense from a modern perspective or wouldn’t be found in a modern house. Like the drop-down ironing board in the kitchen. I love it even though I never iron.