Tilt tension sets how hard the backrest pushes back when you recline. To set it, sit the way you normally work, release any recline lock or limiter, then turn the tension control a little at a time toward the + mark. Stop when the backrest holds you upright with no effort but tips back when you lean on purpose. Then use the lock or limiter, not extra tension, if you want to stay upright for focused work.

Find out which control your chair has

Chairs don’t all use the same control, and they don’t all turn the same way. Check the manual or the markings on the knob before you start.

Chair Tension control To add tension Recline stop or lock
Herman Miller Aeron Long stem with a knob on the right side Turn the knob forward, toward the + sign Tilt limiter on some models: rotate forward to limit recline, all the way back to release
Steelcase Leap Upper back force knob, five complete turns end to end Turn the knob forward Variable back stop with five positions
Steelcase Series 1 No free knob; weight-activated tension Use the dial’s boost setting Upright back lock on the same dial
Serta Works Office Chair (budget) Round knob under the front center of the seat Turn counterclockwise, per the manual Upright-only tilt lock on the height handle: push in to lock, pull out to recline

The Serta manual says counterclockwise stiffens the tilt. Merryfair, another chair maker, tells its owners that clockwise adds resistance. Clockwise depends on whether you look at the knob from the front or from below, so the + and - marks or the manual’s diagram are more reliable than either word.

Steelcase Series 1 has no tension knob: it responds to your body weight, and its dial adds a “boost” setting that Steelcase lists as 20% more tension, so the only tension choice is whether to use boost.

Know what kind of tilt you have

Merryfair’s mechanism guide describes the common types:

  • Center tilt: the pivot sits under the middle of the seat, and the seat and back tilt together, so the front edge of the seat rises as you lean back.
  • Knee tilt: the pivot is near the front of the seat, so the front edge stays low when you recline.
  • Synchro tilt: the back reclines farther than the seat, typically at about a 2:1 ratio.
  • Multi-function (asynchronous) tilt: the seat and back angles are set separately and can each be locked.
  • Weight-activated: the mechanism sets resistance from your weight, so there is no knob or only a coarse setting (Series 1 works this way).

Merryfair notes that on a center-tilt chair the front of the seat rises as you recline, which can lift your feet, so a loose setting there is felt under the thighs as well as in the back. For more on the mechanisms themselves, see synchro-tilt vs simple-tilt mechanisms .

Set it in six steps

  1. Set seat height first. OSHA’s guidance is that the whole sole of your foot rests on the floor with the back of your knee slightly higher than the seat. If the chair has seat depth or lumbar adjustments, set those too, because they change where your weight sits.
  2. Free the recline. Release the tilt lock, or set the tilt limiter or back stop to full recline. You can’t judge tension while the back is locked.
  3. Start in the middle. If you don’t know the current setting, Merryfair suggests starting mid-range. On a Leap that means about halfway through the knob’s five turns.
  4. Lean back and let go. If the backrest drops away as soon as you settle against it, add tension. If you have to push hard to get it to move, reduce tension. Merryfair puts it this way: if the chair throws you backward it’s too loose, and if you have to shove yourself back it’s too tight.
  5. Adjust in small steps. Sit back in the chair after every change before you turn the knob again.
  6. Then set the lock or limit. For typing, hold the back upright with the lock or limiter. Herman Miller says to engage the Aeron’s tilt limiter when you want to sit upright or partly reclined. The difference between the two controls is covered in tilt lock vs tilt limiter .

On a shared chair, tension is set for one person’s weight. Check it each time someone else has used the chair.

When the knob isn’t the problem

  • The seat sinks while you sit. That’s the gas cylinder, not the tilt. Merryfair’s guide makes the same split. See how to diagnose gas lift problems .
  • The knob is at its limit and the back still drops. Merryfair names the tension spring, which goes soft, and the lock pawl, which stops holding an angle, as the parts that usually fail first. It also says tilt mechanisms are usually replaced rather than repaired. Also check that you’re within the chair’s rated capacity. Herman Miller rates the Aeron at 300, 350 or 400 pounds depending on size, and the Serta Works manual lists 250 pounds.
  • The seat or back rocks side to side. Look for loose fasteners. The Serta Works manual says to check all bolts and screws every 90 days. See how to fix desk chair rocking or looseness .
  • The chair creaks as it tilts. See why your desk chair squeaks .

Common questions

Which way do I turn the tilt tension knob?

Follow the markings or manual for your chair. Herman Miller (Aeron) and Steelcase (Leap) say to turn the knob forward to add tension. The Serta Works manual says counterclockwise stiffens its tilt.

Why doesn’t my chair have a tilt tension knob?

It probably uses a weight-activated mechanism. Steelcase Series 1 is one example: it has a three-setting dial instead of a knob.

Should I max out tilt tension so the chair stays upright for typing?

No. Set tension for comfortable support, then use the lock or limiter to stay upright. OSHA’s chair guidance says a backrest should lock in place or be tension adjustable.

Sources

Sources checked October 3, 2026.