Trouble measuring

Out of all my questions I feel this is my silliest but I feel so frustrated. I am trying to knit a sweater, and i have to measure along the way to make it 26 1/2 inches long. i thought i was doing fine but after I binded off it is a few inches too short. My question is what is the best way to measure the length? I have a flexible measuring tape. I would lie it flat on the table to measure but it seems i sometimes got different measurements. . Sorry for the rant but i’m so frustrated with myself. Should i lie it down loosely? should i pull it a little so its kinda of tight?

When I measure my knitting I lie the piece flat on a table or the floor and measure that way. Just make sure you measure the front (or back, whichever you knit next if you are not knitting your sweater on rounds) the same way. And measure them against eachother when you get to that point. That way even if you are a little off with your measurements you can knit the 2nd piece to be the 1st’s length.
Good Luck!

There are a couple of things I do. One is, when measuring, like you, I lay things out on my diningroom table. But I use a wooden yard stick. I don’t stretch or in any way manipulate the piece, I just lay it as it goes.
The other thing, is that I often keep track of rows or rounds, as I go. I put a safety pin in every 10 or 20 or whatever seems to work best for that particular project, and then I go by that count. It may be slightly off in the final measurement, but not by too much, and that way I know I’ve done exactly the same amount of rows for each sleeve, or the fronts and back, etc. Also, I leave in the pins because it makes sewing up the seams easier.

One thing with measuring flat is, when the sweater’s put together and worn, it may stretch out so it’s longer. Hang up the piece for a couple hours, then measure it flat.