How to Switch Between Inches and Centimeters in Your Pattern Tool
Inches and Centimeters: You Choose
One of the most common questions from new users is how to switch between inches and centimeters in their sewing pattern tool. Whether you are in the United States measuring in inches or anywhere else in the world measuring in centimeters, People's Patterns supports both unit systems and makes switching between them effortless.
This matters because sewing is a global craft. Patterns, tutorials, and resources come from all over the world, and you might find yourself needing to work in a unit system that is not your default. Maybe your tape measure shows centimeters but you are following a tutorial written in inches. Maybe you are sewing for someone in another country who gave you their measurements in metric. Whatever the reason, your pattern tool should handle inches and centimeters sewing needs without friction.
People's Patterns lets you work in whichever unit system feels natural to you, and switch whenever you need to. Here is exactly how it works.
Where to Find the Unit Toggle
The unit toggle is available in two places within People's Patterns:
- In the measurement wizard: When you are entering your body measurements, you will see a toggle near the top of the form that lets you switch between inches and centimeters. Switching here affects how your measurements are displayed and entered.
- In your account settings: You can set your preferred unit system as a default so it is pre-selected every time you use the tool.
The toggle is clearly labeled and switches instantly. There is no need to re-enter your measurements when you switch -- the system converts your existing values automatically.
How Automatic Conversion Works
When you switch between inches and centimeters sewing units, People's Patterns automatically converts all your saved measurements. If you entered your bust as 38 inches and then switch to centimeters, the system displays 96.5 centimeters. Switch back and it shows 38 inches again. The underlying precision is maintained through all conversions.
This is especially useful when you are working with measurements from different sources. If a friend gives you their hip measurement as 102 centimeters but you normally work in inches, you can switch to centimeters to enter that number, then switch back to inches for the rest of your workflow. The system handles all the math.
Which Unit System Should You Use?
Use whichever system you are most comfortable with. Here are some practical considerations:
Inches
- Standard in the United States and commonly used in the US sewing community.
- Most US sewing rulers, cutting mats, and tape measures are marked in inches.
- Fractions (like 38 and 1/4 inches) can be less intuitive than decimals for some people.
Centimeters
- Standard in most of the world outside the United States.
- Offers finer granularity: 1 inch equals 2.54 centimeters, so metric measurements have more decimal precision without using fractions.
- Many international sewing patterns, tutorials, and resources use centimeters.
For the purposes of generating accurate patterns, inches and centimeters sewing accuracy is identical. The pattern engine works with precise decimal values internally regardless of which unit system you use for input. Your choice is purely a matter of personal preference and what your tools are marked in.
Entering Measurements in Your Preferred Units
When the unit toggle is set to your preferred system, all measurement fields in the wizard display in that unit. Here is how to enter values accurately in either system.
Entering Inches
People's Patterns accepts inches as decimals. If your bust measures 38 and 1/2 inches, enter 38.5. If it measures 38 and 1/4 inches, enter 38.25. Here are common fraction-to-decimal conversions:
- 1/8 inch = 0.125
- 1/4 inch = 0.25
- 3/8 inch = 0.375
- 1/2 inch = 0.5
- 5/8 inch = 0.625
- 3/4 inch = 0.75
- 7/8 inch = 0.875
Entering Centimeters
Enter centimeters as decimal numbers. If your waist measures 76 and a half centimeters, enter 76.5. Centimeters tend to be more straightforward since the metric system is natively decimal.
What About Your Printed Pattern?
When you generate and download your pattern, the printed PDF reflects your chosen unit system. Seam allowance labels, dimension notes, and the scale verification square are all shown in inches and centimeters sewing units based on your selection. This keeps everything consistent from the measurement entry stage through to fabric cutting.
The scale verification square on page 2 of your PDF is always 2 x 2 inches (or 5 x 5 centimeters in metric mode). Use a ruler marked in the same unit system to verify your print scale.
Tips for Working With Mixed Units
Sometimes you will encounter situations where inches and centimeters sewing units get mixed together. Here are practical tips for handling those situations:
- International patterns and tutorials: If you are following a tutorial that uses centimeters but you work in inches, switch your People's Patterns profile to centimeters temporarily to compare numbers directly.
- Buying fabric abroad: Fabric in metric countries is often sold by the meter. Your People's Patterns materials list shows yardage in your chosen units, so switch to metric before shopping if needed.
- Sewing for someone in another country: If they give you measurements in centimeters, switch to centimeters to enter their numbers into their measurement profile. The pattern will be accurate regardless of the input units.
- Converting in your head: As a quick reference, 1 inch equals approximately 2.5 centimeters. For more precision, 1 inch equals 2.54 centimeters. But you rarely need to convert manually since the tool handles it for you.
Setting Your Default Unit System
To avoid toggling every time you log in, set your preferred unit system as the default in your account settings. Navigate to your account, find the preferences section, and select either inches or centimeters as your default. From that point on, every measurement field, every pattern label, and every materials list will use your preferred units automatically.
You can still override the default with the toggle at any time. The default just saves you one click on each visit.
Start Generating Patterns in Your Preferred Units
Whether you think in inches and centimeters sewing terms, People's Patterns speaks your language. Enter your measurements, pick your units, and start generating custom-fit patterns that are drafted to your exact body. Browse the pattern catalog to find your next project, from a classic tee to chinos to a wide-leg trouser. Your first pattern is free.
Frequently Asked Questions
Can I enter some measurements in inches and others in centimeters?
People's Patterns uses one unit system at a time for consistency, but you can switch between inches and centimeters at any point. The system converts your existing measurements automatically when you switch, so you can enter a measurement in one system, toggle, and continue in the other.
Does switching units affect my pattern accuracy?
No. The pattern engine works with precise decimal values internally. Whether you enter your measurements in inches and centimeters makes no difference to the accuracy of the generated pattern. The conversion is mathematically precise.
Which unit system is more accurate for sewing?
Both are equally accurate for sewing. Centimeters offer finer granularity since 1 inch equals 2.54 centimeters, which some sewists find easier for precise measurements. But inches work just as well. Use whichever system you are more comfortable with and that matches your tools.
Will my printed pattern show inches or centimeters?
The printed pattern includes markings in the unit system you selected. Seam allowances and key dimensions are labeled in your chosen units, whether inches and centimeters sewing notation, so everything is consistent from the screen to your cutting table.
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