Home & Furniture calculator
What Mattress Size Fits My Bed Frame?
Use your measurements for bed frame inside width, bed frame inside length, and desired total fitting allowance to find maximum mattress dimensions.
Enter your measurements
Use this maximum-size calculation when you need to answer “what mattress size fits my bed frame?” Enter bed frame inside width, bed frame inside length, and desired total fitting allowance and the tool returns maximum mattress dimensions using the rule defined for this exact use case.
- Bed frame inside width — Required
- Bed frame inside length — Required
- Desired total fitting allowance — Optional
Maximum mattress dimensions
Enter the measurements above to calculate maximum mattress dimensions.
How the calculation works
V17 calculation: maxMattressWidth=max(0,frameInsideWidth-fitAllowance); maxMattressLength=max(0,frameInsideLength-fitAllowance). The result is reported as Maximum mattress dimensions.
Worked example
Example: Bed frame inside width = 150 cm; Bed frame inside length = 200 cm; Desired total fitting allowance = 2 cm. Result: Max Mattress Length = 198 cm; Max Mattress Width = 148 cm.
Before you decide
Use measured dimensions rather than nominal labels. This page calculates the stated geometry or quantity only; product-specific construction or installation details can still affect the final choice. For what mattress size fits my bed frame, the limiting result on this page is maximum mattress dimensions.
Direct measurement/geometry calculation. No external reference is required for the arithmetic itself; the result is derived only from the user-entered measurements and the formula stored in calculationLogicJson.
Frequently asked questions
What does the Mattress Size Fits My Bed Frame calculator tell me?
It returns maximum mattress dimensions from the measurements entered on this page. The calculation is specific to mattress size fits my bed frame, so the result should be compared with the exact product or specification you are considering.
Which measurements should I take for mattress size fits my bed frame?
Measure bed frame inside width, bed frame inside length, desired total fitting allowance. Use clear, usable dimensions rather than nominal room or product labels.
Should I round the maximum mattress dimensions?
Keep the calculated value for comparison, then choose a real product that meets or stays within the returned maximum mattress dimensions while allowing for the clearances, tolerances or ratings shown by its manufacturer.