Actuation Force vs Bottom-Out Force: What Is the Difference?

When comparing mechanical keyboard switches, you will often see several force specifications. Two of the most important are actuation force and bottom-out force.

A switch might, for example, be listed as having a 45 gf actuation force and a 60 gf bottom-out force. Although both values describe force, they refer to different parts of the keypress.

Actuation force describes approximately how much force is required around the point where the switch registers. Bottom-out force describes the force near the end of the switch's full travel.

Quick choice

Actuation force mainly tells you how light or heavy the switch is to activate. Bottom-out force tells you how firm it feels when pressed all the way down. To properly understand the feel of a switch, it is useful to consider both values together.

1. What is actuation force?

Actuation force is approximately the amount of force required to operate a mechanical switch around its registration point.

The key usually registers before the switch reaches the end of its travel.

As a rough guide:

• 35–40 gf: very light actuation
• 45 gf: light actuation
• 50–55 gf: medium actuation
• 60+ gf: heavier actuation

The lower the actuation force, the less physical force you generally need to register an input.

For a deeper explanation, read our guide to actuation force on mechanical keyboard switches.

2. What is bottom-out force?

Bottom-out force describes approximately how much force is present near the end of the switch's complete travel.

For many switches, this value is higher than actuation force because the spring becomes increasingly compressed as the switch moves downward.

• 50–55 gf: light bottom-out
• 60–65 gf: light to medium
• 65–75 gf: firm
• 75+ gf: heavy

You can learn more in our guide to bottom-out force on keyboard switches.

3. The difference at a glance

Characteristic	Actuation Force	Bottom-Out Force
Point in the keypress	Around registration	Near the end of travel
Mainly describes	How heavy activation feels	How firm the bottom of the stroke feels
Important for	Light activation, rapid inputs	Full keypress feel
Usually	Lower	Higher
Do you always feel it?	Relevant around each registered input	Mainly if you bottom out

4. Example: 45 gf actuation and 60 gf bottom-out

Imagine a linear switch with the following specifications:

• Actuation force: 45 gf
• Bottom-out force: 60 gf

The switch activates relatively lightly but becomes noticeably firmer towards the end of the travel.

In plain English: you do not need much force to register the key, but you feel more resistance when you press it all the way down.

5. Why is bottom-out force often higher?

Most mechanical keyboard switches contain a spring underneath the stem.

As you press the key:

1. the spring begins to compress;
2. the switch reaches its actuation point;
3. you continue pressing;
4. the spring compresses further;
5. the switch eventually bottoms out.

This usually causes the required force to increase throughout the movement.

A simplified example could be:

• Initial force: 30 gf
• Actuation force: 45 gf
• Bottom-out force: 60 gf

6. Which value determines how heavy a switch feels?

Both of them.

Which value matters most depends on your typing style.

• You type very lightly: actuation force and initial force may matter more.
• You fully press every key: bottom-out force becomes more important.
• You use tactile switches: tactile force may be even more important.
• You mainly game: actuation force and pre-travel are often especially relevant.

7. Same actuation force, different feel

Consider these two fictional switches:

Switch	Actuation	Bottom-Out	Feel
Switch A	45 gf	55 gf	Light throughout the stroke
Switch B	45 gf	70 gf	Light activation, firm bottom

Both activate at roughly the same force, but Switch B becomes much heavier towards the bottom.

This is why actuation force alone does not describe the entire switch.

8. Same bottom-out force, different feel

The reverse can also happen.

Switch	Actuation	Bottom-Out	Feel
Switch C	40 gf	60 gf	Light start, noticeable increase
Switch D	52 gf	60 gf	Firmer from the beginning

Although both switches bottom out at 60 gf, Switch D feels heavier during more of the keypress.

9. What does the gap between the two values tell you?

The difference between actuation and bottom-out force can also provide useful information.

• 45 gf → 55 gf: relatively small increase and consistent feel.
• 45 gf → 65 gf: more noticeable increase in resistance.
• 35 gf → 65 gf: very light start with a much firmer bottom.

A larger gap generally means you will notice more resistance building throughout the keypress.

This is not a perfect rule because spring type and the full force curve also matter.

10. How does this work on linear switches?

With linear switches, the comparison is usually the easiest.

There is no tactile bump, so resistance tends to rise relatively smoothly from the top of the keypress towards the bottom.

Actuation force and bottom-out force together therefore give a useful first impression of how heavy a linear switch will feel.

11. How does this work on tactile switches?

With tactile switches, there is another important value: tactile force.

A switch might have:

• Actuation force: 45 gf
• Tactile peak: 62 gf
• Bottom-out force: 58 gf

In this case, the heaviest part of the keypress is the tactile bump rather than the bottom.

This makes tactile switches harder to judge from actuation and bottom-out force alone.

12. What about clicky switches?

With clicky switches, a click jacket or click bar can also introduce an additional force peak.

The heaviest point of the keypress may therefore occur somewhere in the middle of the travel.

For clicky switches, the clicking mechanism should also be considered alongside actuation and bottom-out force.

13. Which value matters more for gaming?

For gaming, actuation force is often more relevant because it affects how much physical force is needed to register an input.

However, pre-travel is also extremely important.

A 45 gf switch with 2.0 mm pre-travel is not necessarily faster-feeling than a 50 gf switch with 1.0 mm pre-travel.

Bottom-out force mainly affects comfort and how heavy rapid repeated inputs feel when you press keys fully down.

14. Which value matters more for typing?

For typing, both can matter significantly.

• Light typist: actuation force may matter more.
• Heavy typist: bottom-out force becomes more noticeable.
• Long writing sessions: the entire force curve may matter more than one number.
• Tactile switch user: tactile force is also essential.

15. Can bottom-out force affect fatigue?

Yes, particularly if you fully bottom out most keys.

A switch with 45 gf actuation and 80 gf bottom-out can feel much more demanding during long typing sessions than one with 45 gf actuation and 55 gf bottom-out.

Both activate just as lightly, but your fingers need to apply considerably more force near the end of the stroke with the first switch.

16. Does lower force automatically mean a better switch?

No.

Lower simply means lighter. It does not mean better.

A heavier switch can offer:

• fewer accidental inputs;
• a more controlled feel;
• stronger key return;
• a preferred feel for people who type firmly.

A lighter switch may instead be more comfortable for gaming or users who prefer minimal resistance.

17. Common mistakes

• Treating actuation and bottom-out as the same thing: they describe different parts of the stroke.
• Comparing actuation alone: the bottom of the keypress may be much heavier.
• Comparing bottom-out alone: the switch may already feel heavy earlier in the travel.
• Ignoring tactile force: on tactile switches, this can be the highest force.
• Assuming lower is always better: switch force is largely personal preference.

Conclusion

Actuation force and bottom-out force describe two different stages of the same keypress.

Actuation force tells you approximately how much force is required around the point where the switch registers. Bottom-out force describes the resistance near the end of the full travel.

A switch can therefore activate lightly but bottom out heavily, or feel relatively consistent from top to bottom.

For a proper comparison, consider actuation force, bottom-out force, pre-travel, total travel, spring design and, where relevant, tactile force.

Browse our linear switches, tactile switches and clicky switches to compare different force profiles.