1. Measure your trampoline (the diameter - from frame edge to frame edge). Jump mats are sold by 'trampoline size' not jump mat size, so if you have a 10ft trampoline you'll need to select what we call a '10ft jump mat' (even though the actual jump mat is approx 8ft).
2. Count your springs. Work your way round under the pads. You may want to mark the first spring with a piece of tape so you remember where you started counting.
3. Measure your spring length. When measuring, measure right from tip to tip (entire spring including the hooks at either end). Bear in mind that if your springs are old and have been used a great deal, they may well have slightly stretched so a 7” spring may well measure 7.5”