What is the Jeans Size Calculator?
Jeans are usually labelled with two numbers, written as W x L — the waist (W) and the inseam length (L), both in inches. This calculator turns your body measurements into those numbers, so you can shop with confidence whether the size chart uses inches, the US/UK system, or European numbers.
How to use it
Pick whether you measured in inches or centimeters. Enter your waist circumference (measure around your natural waistline where the jeans will sit) and your inseam (the inside leg length from crotch to ankle). The calculator rounds each to the nearest whole inch and also estimates the European waist size.
The formula explained
The waist size is simply the waist circumference converted to inches and rounded: \(\text{W} = \operatorname{round}(\text{waist in})\). The inseam is the leg length in inches: \(\text{L} = \operatorname{round}(\text{inseam in})\). European jeans sizes follow a well-known offset of roughly +16, so \(\text{EU} = \text{W} + 16\). If you enter centimeters, each value is divided by 2.54 before rounding.
$$\text{W} \times \text{L} = \operatorname{round}\!\left(\text{Waist (in)}\right) \times \operatorname{round}\!\left(\text{Inseam (in)}\right)$$If you enter centimeters:
$$\text{W} \times \text{L} = \operatorname{round}\!\left(\dfrac{\text{Waist (cm)}}{2.54}\right) \times \operatorname{round}\!\left(\dfrac{\text{Inseam (cm)}}{2.54}\right)$$and the European size is
$$\text{EU} = \text{W} + 16$$
Worked example
Suppose your waist measures 34 inches and your inseam is 32 inches. The calculator returns W34 x L32. The approximate EU size is \(34 + 16 = 50\). So you'd look for jeans labelled "34/32" or EU 50.
FAQ
Should I size up? Rigid (non-stretch) denim and jeans you'll wear with a belt often fit better one size up. Stretch denim usually fits true to size.
Why is the EU size approximate? European brands vary, and +16 is a common convention rather than an exact rule. Always check the brand's own size chart when possible.
Where do I measure the inseam? Use a pair of well-fitting trousers laid flat and measure the inner seam from crotch to hem, or measure your inner leg standing barefoot.
