Write down all ten measurements
Use a thin strip of paper, a pen and a ruler to record the widest part of each nail while your hand is relaxed. Measure both hands separately and label the order from thumb to little finger. Keep width and length as separate measurements. Repeat the reading once; if the figures differ, measure again rather than choosing the number you prefer.
A size chart does not describe every curve
Ask whether the chart describes a flat width or an inside curve, because different measuring methods are not interchangeable. During a dry fitting, look at the side edges and the curve as well as the number. Two pieces with a similar stated width can fit differently. A sample or a sizing kit can make the choice clearer than comparing photographs.
Prepare a useful size list
List five measurements for the left hand and five for the right. Include the units, your preferred shape and an indication of length. Keep a note of the date and measuring method for a future order. If someone helps you measure, review the final list yourself so the finger order and the differences between your hands are not lost.
Separate fitting from styling
For your first order from a new supplier, ask whether a sizing kit or a sample is available. Establishing the fit and choosing a design are two separate decisions. Start with a length that feels familiar during everyday activities, then explore the colours and embellishments you enjoy. The photographs on this demo site illustrate possibilities; the final sizing advice comes from the actual supplier’s chart.