How the hell do I measure stairs?

[countvoncount]

As in the title, I am wanting to buy carpet online, for stairs only, and have absolutely no clue how to measure how much I need
It's a standard straight staircase, no curves or corners, and not doing hall or landing
Could any wise mumsnetters tell me how to measure stairs please?

I mean I would measure the height of a step and the width of a step and add the two together to give carpet per step. Multiply by number of steps, add a bit extra for safety.

Honestly I'd get someone to come out and measure. We had our stairs done last month so got fitters out to quote (as I'm guessing you're not planning to fit it yourself?) and they all measured as part of the free quote. The numbers came out slightly differently depending on whether we wanted a seam (which we never would have thought of at all) plus carpet comes in either 4m or 5m width as standard.

Best left to the professionals!

Presumably you're fixing to grippers that fix on the back of each tread and at the bottom of each riser. (Unless you're using old fashioned stair rods.) So each step is those two lengths added together. And the width is the same for each step. The thing people often overlook is the top step on the landing - you need to measure from where that piece of carpet will start (usually the wall) to the bottom of the riser on the top step. And you need to allow for the width of the landing so you can cut that as one piece, unless you're going to join the widths. Carpet fitting isn't easy. Are you planning on doing it yourself?

ETA: That's the simple case - a turning staircase if obviously more involved!

I think it's just tread + riser x no. of steps.

Absolutely NOT planning on fitting myself!!
I think I'll get the fellows in
Sounds rather complicated, even though I like to consider myself apt at any kind of DIY
Add mathematics and I'm screwed 😂

possible starting point @countvoncount

https://www.omnicalculator.com/construction/stair-carpet

This

Thankyou @beetr00!
What the hell is a "nosing"?
Jeez, what a palava

https://www.merriam-webster.com/dictionary/nosing

@beetr00 well, you learn something new every day!
Can't say I've ever noticed that my stairs have noses 😕

That’s one thing I’d not do, I’d get one of the suppliers in to measure up,