Gas Strut Force Calculator

Gas Strut Calculator — Find Your Exact N Rating

Ordering the wrong strength gas strut is the #1 reason for returns. Enter your panel's weight and mounting measurements below and this free gas strut calculator works out the force (in Newtons) you need, then shows you matching products from our range. Gas struts and gas springs are the same part, so it works just as well as a gas spring calculator.

This calculator is for general DIY jobs — cabinet doors, toolbox & van lids, motorhome hab doors, hatches, gates and similar hinged panels. Replacing a car bonnet or tailgate strut? Force alone won't guarantee the right fit — go straight to Car Gas Struts by vehicle instead.
kg
Weigh it on bathroom scales if you can — a rough estimate is fine otherwise.
mm
Roughly half the panel's width/length if the weight is evenly spread.
mm
Measure along the panel from the hinge to the strut's lower fixing point.
How is this calculated?

We use the standard moment-balance formula used across the gas spring industry for hinged panels:

F = (W × 9.81 × L) / d

F = force needed per strut (N) · W = panel weight (kg) · L = hinge-to-centre-of-gravity distance · d = hinge-to-strut-mount distance. The result is then multiplied by your chosen safety margin and, if you're fitting two struts, split between them.

This is the same simplified method used by gas strut manufacturers for quick sizing. It's accurate enough for the vast majority of DIY and replacement jobs, but it is an estimate — for anything load-bearing over head height, or where safety is critical, double-check against the manufacturer's spec or ask us before ordering.

Worked Example

A 3kg cupboard door, 200mm from the hinge to its centre, with the strut fixed 60mm from the hinge: 3 × 9.81 × 200 ÷ 60 = 98N. Add the 1.3× general-purpose margin (128N) and split it across a pair of struts: about 70N per strut.

Gas Strut Calculator FAQs

Is a gas spring calculator different from a gas strut calculator?
No. Gas strut, gas spring, gas lift and lift support are different names for the same part, so the same formula applies.

What if my result falls between two sizes?
Pick the next size up for a lid that should rise on its own, or the size below if you want it to stay down until lifted. If you're unsure, send us your measurements and we'll recommend the right strut.

Can I use this for an ottoman bed?
Ottoman beds use a different hinge geometry, so the quickest route is to match the N rating printed on your old struts — see our ottoman bed gas struts and the bed force guide.

Where can I see all strut forces and lengths?
Browse every force rating in our gas struts range.

Not sure about end fittings? Check the Ball Stud & Clevis End Size Chart, use the Fitting & Bracket Finder, or grab the printable sizing chart to keep handy.