What Size Trampoline Should I Get? Frame Size, Mat Size and the Clearance Makers Ask For

Measure the yard first

CPSC's guidance is to place the trampoline away from structures, trees and other play areas, on ground that is level. Pace out the largest flat area with nothing overhead (Jumpflex's HERO is 8.9 ft tall to the top of the net; ACON's 16 HD is 130 in) and nothing hard within reach of the net. Then subtract the clearance below. Slopes matter: a round frame can be shimmed on a slight grade, a rectangle cannot, and any frame on a slope needs anchoring on the downhill legs first; see how to anchor a trampoline.

What each maker asks for around the frame

Clearance figures as published on each maker's page, September 22, 2026. Where a maker gives none, the last column is our arithmetic using 3 ft.

Mat size vs frame size

The number on the box is the frame diameter. The mat is smaller by the width of the springs and pad on both sides: Jumpflex publishes a 12.1 ft mat inside its 14 ft HERO and a 10.5 ft mat inside the 12 ft FLEX, and warns buyers to watch for brands that advertise a big overall diameter with a small mat. Springfree quotes the mat directly (10 ft mat on the R79, which needs a 20 ft space), so a "10 ft Springfree" and a "12 ft spring trampoline" have similar jumping areas. Comparing mats, not frames, is the honest way to compare sizes across brands.

By family: 1, 2 or 3 kids

One child. A 12 ft round (10-11 ft of mat) is plenty and is the easiest size to anchor and cover. Two kids. Still one at a time on the mat; a 14-15 ft round gives the jumper more room and gives the waiting child no excuse to climb in. Three or more. The temptation is a 16 ft or a rectangle so they can all jump; CPSC's rule is one at a time and the AAP's finding is that most injuries happen with multiple jumpers, so the extra size buys space for one bigger jumper, not room for a crowd. If any child is under 6, CPSC says no full-size trampoline at all; see trampoline age recommendations. Teenagers and adults should size for the printed limit, not the diameter: trampoline weight limit.

One pick per size

Mistakes to avoid

• Buying the frame size the yard fits with no clearance. The clearance is where a child lands if the net fails.
• Buying a 16 ft so three kids can jump together. One at a time is the rule at any size.
• Putting a rectangle on a slope. Long frames show the grade; see round vs rectangle.
• Forgetting the height. A 9 ft net under a tree limb or a roof eave is a problem the tape measure would have caught.