The £200 Blind Measuring Mistake And Why Even I Get My Measurements Checked

I was measuring for blinds at a customer's home in Barrow upon Soar recently when she asked me a fairly straightforward question.

“Can I just replace the fabric on my vertical blinds?”

Absolutely.

If the headrail is still in good condition, there's often no reason to replace the whole blind. We can simply replace the vertical blind fabric instead.

So I started measuring.

And almost immediately, something didn't look right.

These Blinds Looked Almost New

The fabric was in really good condition.

In fact, it looked almost new.

But every single louvre was catching on the window sill.

Normally, when I see something like that, I start wondering what's changed since the blinds were originally fitted.

“Have you had new window boards fitted?” I asked.

No.

“Have the window recesses been replastered?”

No.

Then she told me what had happened.

The fabric was almost new.

She'd ordered replacement vertical blind slats online, measured them herself and spent more than £200.

There was just one problem.

They didn't fit.

She hadn't fully understood how the replacement fabric needed to be measured, so the slats she'd ordered were too long.

Now she had more than £200 worth of almost-new blind fabric catching on the sill.

The online option that was supposed to save her money had ended up doing exactly the opposite.

Does That Mean You Shouldn't Buy Blinds Online?

Not at all.

And I think that's important to say.

Buying blinds online can be a perfectly sensible way to save money.

If you know the product you're buying, you're comfortable measuring your windows and you're happy fitting the finished blinds yourself, why pay someone else to do those things for you?

For plenty of people, online blinds make complete sense.

But you're taking on one responsibility yourself that you'd normally be handing over to somebody like us.

Getting the measurements right.

And that's where things can get expensive.

Because measuring a blind isn't always as simple as measuring the width and drop of a window.

You need to know exactly what you're measuring, where you're measuring it from and, crucially, what measurements the manufacturer actually needs from you.

Get one of those things wrong and a perfectly well-made blind can arrive that simply doesn't fit.

We've Seen the Same Thing With Perfect Fit Blinds

The customer in Barrow upon Soar isn't the only person we've visited after an online blind order hasn't gone to plan.

We recently visited another customer in Wigston who'd run into problems after ordering Perfect Fit blinds online.

Again, the issue wasn't necessarily the blind.

It was understanding exactly what needed to be measured.

Products such as Perfect Fit blinds can require more information than simply the width and height of the glass. Details about the window and how the blind fits to it can matter too.

If you've done it before and know what you're looking for, that's fine.

If you haven't?

It can become a fairly expensive way of learning.

And here's the thing I think people sometimes overlook.

Even professionals can get measurements wrong.

I've Been Measuring Blinds for More Than 30 Years And I Still Get Checked

I've been measuring windows for blinds for more than 30 years.

I've measured thousands of them.

Bay windows. Bi-fold doors. Conservatories. Rooflights. Schools. Offices.

And plenty of windows that aren't remotely as square as they first appear.

After that amount of time, you'd probably expect me to be pretty confident with a tape measure.

I am.

But do you know what?

I can still occasionally make a mistake.

We're human.

That's why I don't rely on 30 years of experience alone.

When my measurements go back to our office in Leicester, another experienced member of our team checks them.

They know the products. They know what the measurements should look like. And if something doesn't add up, they'll question it.

Sometimes I'll get a phone call.

“Phil, are you sure about this size?”

Or:

“That doesn't look right for that blind. Can you check it?”

And occasionally I'll go back over my measurements and realise they're right to question me.

I'd much rather get that phone call than manufacture a blind that doesn't fit.

Because experience doesn't mean you never make a mistake.

Experience also means knowing mistakes can happen and having a system designed to catch them before they become expensive.

You're Not Paying Someone Just to Hold a Tape Measure

This is one of the biggest differences between ordering blinds online and using a professional measuring and fitting service.

Yes, you're paying for someone's time.

But you're also paying for them to know what needs measuring in the first place.

You're paying for experience that tells them when something doesn't look quite right.

You're paying for somebody else to check those measurements before the blind is ordered or manufactured.

And there's another difference that's probably even more important.

You're deciding who carries the risk if something goes wrong.

If you measure a blind yourself, send those measurements to an online company and the finished blind doesn't fit because the measurements were wrong, that's generally going to be your problem.

You've supplied the measurements.

But if we've measured your windows and we've got those measurements wrong?

That's our problem.

Not yours.

We're responsible for putting it right.

And I think that's an important distinction when you're comparing the price of buying blinds online with having somebody come to your home to measure and fit them.

You're not simply comparing the price of two blinds.

You're comparing two different levels of service, responsibility and risk.

So, Should You Measure Blinds Yourself?

For some people, absolutely.

We're certainly not going to tell everyone they need to have their blinds professionally measured and fitted.

If you've fitted blinds before, understand the product you're ordering and feel confident following the manufacturer's measuring instructions, buying online could save you a decent amount of money.

But I'd give you one simple piece of advice.

If you're halfway through measuring and find yourself looking at the instructions thinking:

“I'm not completely sure what they mean by that…”

Stop.

Don't guess.

Ask the company you're ordering from to clarify exactly what they need before you place the order.

And if you're still not confident, consider getting somebody to measure for you.

Because there's nothing wrong with trying to save money by measuring and fitting blinds yourself.

But the saving only exists if the blind fits when it arrives.

Unfortunately, our customer in Barrow upon Soar learned that lesson with more than £200 worth of almost-new vertical blind fabric.

And despite measuring blinds for more than 30 years, it's exactly why I'm still quite happy for somebody to check my measurements too.

About Phil Coleman
Phil Coleman is the fifth generation of his family to run Barlow Blinds, a Leicester business that has been making blinds since 1887. With over 30 years of hands-on experience, Phil has played a leading role in shaping industry standards including being part of the team that wrote the only NVQ qualification for blind and shutter installers. He also serves on the Management Committee of the British Blind & Shutter Association (BBSA), helping to set best practice across the trade. Under his leadership, Barlow Blinds has remained true to its founding principle: “It’s not our job to find customers for our blinds, it’s our job to find the right blinds for our customers.”

Article Review & Accuracy

Reviewed by: Phil Coleman, Managing Director, Barlow Blinds
Last reviewed: September 2026

Our promise

If new evidence, products or British Standards change our advice, we'll update this article. If we make a mistake, we'll correct it.

This article forms part of the Barlow Blinds Knowledge Centre and is written or personally reviewed by Phil Coleman, drawing on more than 35 years' experience, guidance from the British Blind & Shutter Association (BBSA), British Standards where applicable, manufacturer technical information and real customer feedback.

Major updates to this article are shown at the top or bottom of the page.