# How to measure a trampoline

Please read the page about trampoline sizes to understand how many different diameter exist and how easy it is to mistake the real dimension of your own trampoline. A 2 or 3 cm error in the diameter can result in a soft mat or, on a contrary, in too much tension on the spring.
To be on the safe side, we highly recommend that you check your trampoline for the real size.

### Do not trust what is written on paper :

• Instructions supplied with your trampoline might be misleading.
• Technical data indicated on internet pages of the supplier or the manufacturer might be outdated.

### Measure once, then once again, then cross-check and measure another time if necessary.

Steps to measure the real size of your trampolineÂ :

• The frame must be mounted and the mat installed so that the frame is normally strained.
• Measurement must be taken from the outside of the frame to the outside of the frame.
• Do not think that measuring one diameter is enoughÂ : your frame may have changed over the year and have today an oval form or another weird shape.
• Measure one diameter (in the North – South direction for example).
• Then measure another diameter from a different position.
• The real diameter should be the average of the two results.
• Of course, you can measure a few other diameter if you want to minimize the chance of mistake.

TrickÂ : Not everyone has at home aÂ measuring tape long enough to size the diameter of a 14ft trampoline. In that case, you will need a long rope, a long string or even a roll of any kind :

• Two person are required, one of each side of the trampoline
• Tense the rope or string over the all frame
• Make a mark on the rope.
• You can this way quickly make a few measurement on different diameter direction and you will quickly know which one of those mark is the average one.
• Then, measure bits by bits the rope in order to obtain the real dimension of your trampoline.

Measure the radius and multiply by two? This is an easy way to do the job but this is also too inaccurate. The centre, representing by a marking is a bit lower than the frame and can simply not be in the centre any-more. Measure the external frame is always the best solution.