How to Measure Circular and Rectangular Trampolines

There’s a lot of confusion surrounding what constitutes a trampoline’s size. As an owner, though, it’s crucial to know the industry recognised size so you can buy the correct accessories for it. It’s equally important to know how to measure your trampoline in relation to its shape. See below for our quick and easy guide on measuring your trampoline. Happy bouncing!

Why would you need to measure a trampoline?

Firstly, you might be wondering why you’d need to measure a trampoline. Well, you need its measurements to securely fit a safety mat and enclosure, while also deciding where you’re going to position it. Before we cover accessories though, let’s start with the measuring basics.

How to measure circular trampolines

Parents bouncing their child on a trampoline.

Start at one side of the trampoline’s frame and measure it to the other side across the trampoline’s centre. Next, measure the frame diameter again, but this time measure perpendicular to your first measurement. Finally, calculate the average size of the two measurements for an accurate reading of your trampoline – calculating the average allows for any bends in the frame.

Note that the size of a circular trampoline is calculated by measuring the diameter of the metal frame, not the mat. Also bear in mind that you should only measure the frame if all the springs are securely attached and the mat is correctly fitted.

How to measure rectangular trampolines 

Like circular trampolines, rectangular trampolines should be measured by the frame and not the mat.

Start at the trampoline’s outer metal edge on either of the two short sides. Then measure straight across to the opposite side of the frame. Next, measure the frame diameter of the two long sides. The sum of these two measurements constitute the dimensions of your rectangular trampoline.

Measuring for safety mats

When fitting or replacing your safety mat, you’ll require the following three measurements:

  • Trampoline frame size
  • Number of v-rings
  • Spring size

Trampoline frame size

Firstly, measure your trampoline’s frame according to the guidelines above.


Next, you’ll need to count your v-rings. If you have your mat, chalk on a starting point to prevent any counting mishaps and count its v-rings. If you don’t have your mat, count the holes on the trampoline’s top rail. The v-ring total should match the number of springs.

Spring size

When it comes to determining the size of your springs, it’s best to measure three springs that aren’t overstretched so your calculations are consistent. You can check if they’re are stretched by sliding a sheet of printer paper through the spring’s coils – if it goes through, they’re overstretched, which will ultimately give an inaccurate mat measurement.

Measuring trampoline enclosures

Start by measuring your trampoline’s frame first (see above). Next, determine which enclosure poles you have (top ring, straight pole, arch, straight curved). Then, count the number of complete poles your enclosure has. A full arch equates 1 pole/1 arch and remember that top rings are counted separate from vertical poles. You’re now ready to fit the safety enclosure.

Positioning your trampoline

Buy the right size trampoline

Your trampoline should be age appropriate. Generally, it’s accepted that a full-size trampoline of 6 ft+ is appropriate for children aged 6 years and above.

Space available

Consider the space available for your trampoline. As a rule of thumb, there should be at least 2.5m of clear space around the circumference of the trampoline. If you have a safety enclosure fitted, however, you can reduce this to around 1m.

Level ground

Trampolines should always be installed on level ground. If situated on a slope, users will gravitate to the trampoline’s lower edge, leading to falls. If the ground happens to be slightly uneven, however, improvise by creating small channels in the soil to allow the trampoline legs to sink where necessary. If the slope is too steep though, you may need to fashion a terrace that provides a flat area to safely accommodate the trampoline.

Soft ground

It’s best to install your trampoline on soft ground to absorb impact. Bark is a good option as it’s extremely proficient at this, while it also provides a handy drainage solution and supresses weeds. Bear in mind, if you position your trampoline on grass, you’ll need to move it before mowing the lawn.

While prioritising soft surfaces, you should actively avoid hard ones like tarmac and concrete. If these are your only option though, a safety enclosure becomes an instant essential. You can further reinforce your little ones’ safety by placing some soft mats around the entrance area.

After establishing the best surface for your trampoline, attach some rubber feet to the U-shaped legs to reinforce impact absorption.

Clear space above

To reduce the likelihood of injuries and prolong your trampoline’s lifespan, avoid placing your trampoline under trees, washing lines or overhead cables.

Safe position

While trampolines are heavy, their equipment (enclosure and mat) can act as a sail; therefore, in strong winds, the trampoline may lift off the ground. To combat this, ensure the trampoline is situated in a space that’s protected from the prevailing wind; a trampoline anchor is also an invaluable tool in this instance.

Drainage and soil depth

Some trampoline owners sink their trampoline to ground level, which eradicates the need for a safety enclosure. If you decide to do this, ensure the site has adequate drainage and soil depth to enable a hole to be dug to allow it to sink.

Soft ground around the entrance

Ensure the entrance’s surrounding area is soft as children often forget to close the entrance, heightening the risk of injury.

Shop our full range of trampolines

All Round Fun is operated by All Retail LTD registered in England with company number 06534618 whose registered office is at Davrom House 21 Lyons Road, Trafford Park, Manchester, England, M17 1RN

Copyright 2021 All Round Fun | Website by ATTAIN