SWG to mm Calculator
Convert Standard Wire Gauge (SWG) to millimeters and vice versa. Includes wire visualization and resistance calculation.
Resistance Calculation
Resistance for 10 meters of wire at 20°C
Common SWG Sizes Reference
| SWG | Diameter (mm) | Area (mm²) | Max Current (A) | Typical Use |
|---|
🔧 SWG to mm Calculator – A Handy Tool for Effortless Wire Gauge Conversion
Ever stood in front of a workbench, wire in hand, wondering, “What size is this in millimeters?”
If yes, you’re not alone — and you’re in the right place.
Our SWG to mm Calculator is built to clear that confusion in a blink. Whether you’re crafting jewelry, fabricating sheet metal, or wiring up your next DIY project, this tool helps you convert Standard Wire Gauge (SWG) sizes to millimeters — instantly and accurately.
Try this tool also: AWG to mm calculator
Let’s Break It Down: What is SWG, Really?
SWG, or Standard Wire Gauge, is a British imperial unit used to measure the diameter of wires. Sounds simple, right?
But here’s the twist…
Unlike metric systems that follow logical, even intervals, SWG jumps around. For example:
- 12 SWG = 2.641 mm
- 18 SWG = 1.219 mm
- 24 SWG = 0.559 mm
The difference between sizes isn’t consistent. That means you can’t just multiply or divide — you need a reference table, or better yet, a smart calculator like this one.
Why Does This Matter?
Because precision matters.
The thickness of a wire can affect:
- Electrical conductivity
- Material strength
- Flexibility
- Weight and cost
Whether you’re soldering delicate silver loops or installing industrial-grade cable, knowing the exact millimeter size can make or break the job.
Introducing: The SWG to mm Calculator
This isn’t just another dull calculator.
It’s a tool built by people who understand what you’re dealing with — and want to make it easier.
What It Does:
- You select an SWG number
- It instantly gives you the precise millimeter diameter
- No math, no charts, no second-guessing
Example:
Choose 20 SWG → You instantly see 0.914 mm.
Fast. Clean. Accurate.
Why Our Calculator Stands Out
Accurate to the Decimal
We pull from verified engineering standards, ensuring results accurate up to three decimal points.
Built for Humans
No clutter. No ads. Just a smooth experience across phones, tablets, and desktops.
Covers the Full Range
From 7 SWG (largest) to 36 SWG (finest) — it’s all here in one place.
The Deep Science Behind SWG and mm
Let’s get real for a moment. You might wonder:
Why is SWG so odd? Why not just stick with mm?
Well, SWG dates back to the early days of British industrialization, where wire was measured based on how many times it was drawn through a die. Each pass made it thinner, but not evenly. So instead of a linear scale, SWG developed into a logarithmic-ish system.
That’s why:
- SWG 10 to SWG 11 is a big jump
- SWG 30 to SWG 31 is much smaller
Converting this manually is a pain — and that’s exactly the problem this tool solves.
How to Use the SWG to mm Calculator (Step-by-Step)
Find your SWG number on the tool’s dropdown menu.
Click or tap to select it.
- Instantly, you’ll see the millimeter equivalent.
- Use the result in your designs, repairs, or product listings.
- You can even bookmark the page for quick access during projects.
Handy Reference Table (Top 10 Common Conversions)
| SWG No. | Diameter (mm) |
|---|---|
| 8 | 4.064 mm |
| 10 | 3.251 mm |
| 12 | 2.641 mm |
| 14 | 2.032 mm |
| 16 | 1.626 mm |
| 18 | 1.219 mm |
| 20 | 0.914 mm |
| 22 | 0.711 mm |
| 24 | 0.559 mm |
| 30 | 0.315 mm |
Who Will Love This Tool?
- Jewelry Makers – Find the perfect wire for earrings, rings, and wraps
- Electricians – Match the right size for voltage and current capacity
- Metalworkers – Precision is key when cutting or welding
- DIYers & Hobbyists – No more guesswork with pliers in one hand and Google in the other
Related Search Terms We Help You Cover
(for those who landed from search engines)
- “What is 22 SWG in mm?”
- “Wire gauge to mm chart”
- “Convert SWG to millimeter”
- “Standard wire gauge mm size”
You’ve probably typed one of those — now you’ve found the perfect answer.
Frequently Asked Questions (FAQs)
What’s the difference between SWG and mm?
SWG is a gauge system based on wire-drawing steps. Millimeters are metric and universal. You need to convert SWG into mm for accuracy in modern applications.
Is this calculator accurate?
Yes! We use standard SWG-to-mm tables recognized by engineers and manufacturers globally.
Is SWG the same as AWG?
Nope. AWG (American Wire Gauge) and SWG have different values. Always make sure you’re using the correct system for your region or spec sheet.
Can I use this on mobile?
Absolutely. Our calculator is responsive and works on all modern devices. Perfect for workbenches, studios, and classrooms.
Can I embed this tool on my own site?
Not yet — but we’re working on a widget version! Stay tuned.
Final Words: Why This Tool Matters
In technical work, details matter. The difference between 0.914 mm and 1.219 mm might seem tiny — but it can affect current capacity, product durability, and even aesthetics.
With our SWG to mm Calculator, you don’t just save time — you work smarter, build better, and avoid costly mistakes.
Try it now, bookmark it forever, and share it with anyone who works with wire.