Linear Inches Calculator

Linear Inches Calculator

Calculate linear inches (L + W + H) for luggage and baggage to check airline size requirements. Essential for travelers planning carry-on and checked bags.

Last updated: March 2026 | By Patchworkr Team

What are Linear Inches?

Linear inches is a measurement used by airlines to determine luggage size by adding together the length, width, and height of a bag. The formula is simple: Linear Inches = Length + Width + Height.

Airlines use this single number to quickly assess whether your baggage meets their size restrictions without needing to check each dimension individually. It's a standardized way to ensure luggage fits in overhead bins, under seats, or meets checked baggage requirements.

Most airlines have three categories: Personal Items (≤45"), Carry-On Bags (≤62"), and Checked Bags (≤115"). Anything exceeding 115" is typically considered oversized and may incur additional fees.

How to Calculate Linear Inches

Step-by-Step Process

  1. Measure the Length - Find the longest side of your luggage in inches
  2. Measure the Width - Measure the side perpendicular to the length
  3. Measure the Height - Measure from bottom to top, including wheels and handles
  4. Add them together - Sum all three measurements to get linear inches

Formula

Linear Inches = Length + Width + Height

Standard Airline Limits

Personal Item:≤ 45 inches
Carry-On Bag:≤ 62 inches
Checked Bag:≤ 115 inches
Oversized:> 115 inches

Note: Specific limits vary by airline and ticket class. Always check your airline's policy.

Important Measurement Tips

  • Include wheels and handles in your measurements
  • Measure the bag when fully packed (soft bags may expand)
  • Use inches, not centimeters (or convert: 1 inch = 2.54 cm)
  • Round up to the nearest half-inch to be safe

Real-World Example

Checking a Standard Carry-On Suitcase

Scenario:
You're flying with United Airlines and need to verify your suitcase meets their carry-on size limit of 62 linear inches.
Measurements:
Length: 22 inches
Width: 14 inches
Height: 9 inches
Calculation:
Linear Inches = 22 + 14 + 9
Linear Inches = 45 inches
Result:
✅ 45 inches

Your suitcase is well under the 62-inch carry-on limit! It actually qualifies as a personal item and could fit under the seat in front of you.

Frequently Asked Questions

Do I include wheels and handles in measurements?

Yes! Always include wheels, handles, and any external pockets when measuring. Airlines measure the total external dimensions of your bag.

What happens if my bag exceeds the limit?

For carry-ons, you may be required to check it (often with a fee). For checked bags exceeding 115", you'll typically pay oversized baggage fees ranging from $100-$300+.

Are linear inches the same as cubic inches?

No. Linear inches add the three dimensions (L+W+H), while cubic inches multiply them (L×W×H). Airlines use linear inches, not volume.

Do all airlines use the same limits?

No. While 62" for carry-on and 115" for checked bags are common, budget airlines often have stricter limits. Always check your specific airline's policy.

Can I convert centimeters to linear inches?

Yes. First convert each dimension from cm to inches (divide by 2.54), then add them together. Example: 56cm = 22", 35cm = 14", 23cm = 9" → 45 linear inches.

What about weight restrictions?

Linear inches measure size, not weight. Airlines have separate weight limits (typically 50 lbs for checked bags, 15-25 lbs for carry-ons). You must meet both requirements.

Does the orientation of the bag matter?

No. Linear inches are the same regardless of how you orient the bag. 22+14+9 = 14+9+22 = 45". The order doesn't matter in addition.

What if my bag is soft-sided and expandable?

Measure it when fully packed and expanded. Soft bags can bulge significantly when filled, potentially exceeding limits even if empty dimensions are fine.

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