UK Pound Coin Dimensions: A Complete Guide for 2026
Posted by: Ian Stainton • 3 Apr 2026
If you’re sorting through a jar of old change, you’ve probably noticed that not all pound coins are the same. The UK has two versions: the classic round pound and the newer 12-sided coin. Knowing the difference is crucial, especially when you want to exchange foreign coins, as their weights and sizes vary. Our fast, hassle-free service makes it easy to turn that collection into cash, with no need to sort anything.
The original round £1 coin, which was in circulation from 1983 until 2017, has a diameter of 22.5mm and weighs a solid 9.5g.
In contrast, the current 12-sided pound coin, introduced in 2017, has a slightly larger maximum diameter of 23.43mm but is noticeably lighter, tipping the scales at just 8.75g. This bimetallic coin also has a different composition and distinctive edge features, making it easy to tell apart by feel alone.
Quick Comparison of UK £1 Coins
When you’re weighing a big bag of mixed coins, these small differences in weight can add up. That’s why our weight-based estimation tools rely on having accurate data for each coin type. Getting it right means we can give you a more precise, upfront estimate for your leftover foreign currency.
This quick reference table breaks down the key differences at a glance.
UK £1 Coin Specifications Quick Reference
| Specification | Original Round Pound (1983–2017) | Current 12-Sided Pound (2017–Present) |
|---|---|---|
| Weight | 9.5g | 8.75g |
| Diameter | 22.5mm | 23.43mm (point to point) |
| Thickness | 3.15mm | 2.8mm |
| Composition | Nickel-brass | Bimetallic: Outer ring (nickel-brass), Inner ring (nickel-plated alloy) |
| Edge | Milled with inscriptions | Alternating milled and plain sections on its 12 sides |
As you can see, the newer coin is a little bigger but also lighter and thinner. These specifications are exactly what we use to sort and value your currency quickly and accurately.
This difference in weight is vital for our streamlined process, which allows us to convert your old and new coins without you needing to sort them beforehand. It’s a key part of how we provide a fast, easy, and hassle-free service trusted by major brands, including charities, supermarkets, airports, and police forces across the UK.
You can learn more about how these metrics come into play in our guide to UK coin weight calculations.
The Original Round Pound Coin Explained
For over three decades, the original round £1 coin was a familiar sight in purses and pockets across the UK. This iconic coin was a staple of daily life until it was officially demonetised in October 2017.
A major reason for its withdrawal was the growing problem of counterfeits. By 2016, it was estimated that an incredible one in every 33 round pound coins in circulation was a fake, making it difficult for people and businesses to trust them.
If you're sorting through old or obsolete currency, it’s useful to know the key features of the genuine round pound.
- Weight: 9.50 grams
- Diameter: 22.50 mm
- Thickness: 3.15 mm
- Composition: A single-colour nickel-brass alloy
Even though these coins are no longer accepted in shops, we make it fast and easy to exchange your old pound coins for cash. We are a trusted partner for individuals and organisations, providing a 100% guaranteed service. You can find out more about their journey into circulation by reading up on when the pound coin was introduced.
A Closer Look At The 12-Sided 'Nations of the Crown' Coin
First appearing back in 2017, the modern 12-sided £1 coin is widely praised as one of the most secure coins in circulation anywhere in the world. Its distinctive bimetallic design and unique shape were introduced specifically to tackle counterfeiting.
This new coin is a bit lighter and slimmer than its predecessor, weighing in at 8.75g with a thickness of 2.8mm. Its maximum diameter, measured from point to point, is 23.43mm. These UK pound coin dimensions aren't just trivia; they're crucial for businesses, charities, and anyone handling large volumes of mixed currency. You can dig deeper into the official specifications on this handy one pound coin guide.
Knowing these exact weights and measures is what makes our exchange service so straightforward. When you want to convert foreign coins and banknotes, our online weight calculator uses these precise details to give you a quick and accurate estimate. It’s all part of our fast, easy, and hassle-free process—no need for you to sort through anything yourself!
How Coin Dimensions Impact Currency Exchange
When you’re dealing with a big bag of unsorted foreign coins, you might be surprised to learn that it's their weight that often determines their value. The difference in UK pound coin dimensions is the perfect real-world example of why this matters.
Put simply, 1kg of the newer, 12-sided £1 coins is worth more than 1kg of the old round pounds. This is because the new coin is lighter (8.75g) compared to the old one (9.5g), meaning you get more individual coins for every kilo.
For retailers and those looking to donate foreign coins to charity, this difference adds up. They know that 1kg of new £1 coins is worth about £114, while 1kg of the old, heavier ones works out to be around £105. You can read more about how coin specs impact value in this interesting breakdown.
That's where our service comes in. Trusted by everyone from airports to police forces, we make turning your mixed coins into cash completely painless. Our online wizard uses weight to give you a quick, hassle-free estimate with no need to sort your coins. We guarantee a 100% fair return, making it easy to exchange that big jar of change you've been holding onto.
Your Fast, Easy, and Trusted Currency Exchange Solution
So, you've learned about the different pound coins. But what do you do with that jar of mixed currency sitting on the shelf? Whether it's full of old round pounds, leftover holiday money, or even obsolete banknotes, we offer a fast, professional, and hassle-free way to exchange them.
The best part? There’s absolutely no need to sort your coins. Just pop your entire collection in a package and send it to us – we'll handle the rest.
A Simple and Trusted Process
We've built our reputation on providing a transparent, professional service that's trusted by some of the biggest names around, including major supermarkets, airports, charities, and even police forces. Our friendly team is here to provide helpful advice and real-world insights to make your exchange simple.
To make things completely risk-free, we stand by our 100% happiness guarantee. If you’re not satisfied with our valuation for any reason, we’ll return your currency to you, free of charge. Ready to exchange foreign coins and notes?
Just head over to our homepage at We Buy All Currency to get started.
Frequently Asked Questions About Pound Coins
Can I Still Exchange Old Round Pound Coins At a Bank?
If you've tried taking old round £1 coins to your high street bank, you've probably found they're no longer accepted. While a few branches might still take deposits from their own customers, this isn't a guaranteed service and can be hit-or-miss.
Our service offers a fast and 100% guaranteed way to exchange any old pound coins you have, turning that forgotten stash into real, spendable cash without any fuss. It’s easy and hassle-free.
What if I Send a Mix of Old Pounds and Foreign Coins?
That’s absolutely fine! In fact, that’s what our professional service is designed for. One of the biggest headaches with leftover currency is having to sort it, but with us, there's no need to sort your currency.
Simply send everything to us in one package—whether it's leftover holiday money, obsolete currency, or a mix of coins and notes. Our experienced team uses specialist equipment to identify and value every single item for you. You'll get a single, clear payment for the whole lot.
How Does Your Weight-Based Estimate Work?
Our online wizard is a helpful tool for getting a quick estimate, especially if you have a large collection of coins. It gives you a reliable idea of what your currency might be worth before you even send it.
Once your coins arrive, we do the precise work of sorting and weighing them accurately. We then calculate the final value based on the most current exchange rates. Plus, with our 100% guarantee, if you're not happy with the final valuation for any reason, we’ll return your currency to you completely free of charge.
Ready to convert foreign coins and notes? We Buy All Currency makes it fast, easy, and secure. Our trusted service is 100% guaranteed. Visit us at https://www.webuyallcurrency.com to get your hassle-free quote today