Slider selects the wrong value when tapping on lower-half divisions

Steps to reproduce

Create a Slider with:

min: 1
max: 10
divisions: 10

Run the app.
Tap directly on any lower-half division, example:

Tap on 3 → value becomes 2
Tap on 4 → value becomes 3

Tap on higher values (e.g., 6, 7, 8, 9, 10) → the slider selects the correct value.

Expected results

Tapping exactly on a division point (e.g., 3 or 4) should select that exact value.
The slider should not round down unless the tap is closer to the previous division.

Actual results

When tapping on divisions in the lower half of the range, the slider snaps to the previous value instead of the intended one.
Only values 6 and above behave correctly and select the exact tapped division.
The rounding behavior is inconsistent across the range.

Code sample

          Slider(
            min: min.toDouble(),
            max: max.toDouble(),
            value: _value.toDouble(),
            divisions: 10,
            label: '$_value',
            onChanged: (value) {
              setState(() {
                _value = value.toInt();
              });
            },
          ),

Screenshots or Video

Screenshots / Video demonstration

Screen.Recording.2026-03-31.at.17.36.58.mov

Flutter Doctor output

Doctor output

[✓] Flutter (Channel stable, 3.41.3, on macOS 26.4 25E246 darwin-arm64, locale en-YE)
[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 26.1)
[✓] Chrome - develop for the web
[✓] Connected device (4 available)
[✓] Network resources

• No issues found!

Fixed the slider step calculation by correcting the divisions value. Previously, using divisions: 10 with min: 1 and max: 10 was causing uneven step values because Flutter calculates each step as (max - min) / divisions, resulting in decimal increments instead of whole numbers. Updated the implementation to use divisions: max - min, ensuring the slider now moves correctly in proper integer steps from 1 to 10.

With your code:
step = (max - min) / divisions
min = 1
max = 10
divisions = 10
So the slider moves like: 1.0, 1.9, 2.8, 3.7, 5.5, 6.4, 7.3, 8.2, 9.1, 10
Rounding this of will become : 1, 2, 3, 4, 6, 6, 7, 8, 9, 10

Correction

min = 1
max = 10
divisions = 9

Slider will move: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

@mu7mmd

@mu7mmd I think it would be better to use:

onChanged: (value) {
  setState(() {
    _value = value.round();
  });
},

instead of:

onChanged: (value) {
  setState(() {
    _value = value.toInt();
  });
},

The reason is that .toInt() simply truncates the decimal part (e.g., 2.99 becomes 2), while .round() rounds to the nearest integer. This helps compensate for small floating-point imprecisions and ensures the correct value is selected when tapping on a division.

@mu7mmd

@mu7mmd Thanks for the detailed report. Labelling for team-design to investigate further.

@bhpy247

The solution provided by @bhpy247 works, subtracting the max from the min resolves the issue. However, I’m not sure whether this is intended behavior or simply a workaround for an underlying rounding problem. Thank you @bhpy247

This definitely looks like a bug. Feel free to tag me for review if anyone is interested in filing a PR!

@bhpy247

I think the behavior you are seeing in sample code is the intended result of the math used:

As @bhpy247 described, the sample code starts from 1 and set the max to 10, the total distance is 9. If we want each step to advance by exactly 1 (yielding integer values), the number of divisions should be 9 instead of 10.

If use 10 divisions, each step becomes 0.9 (resulting in values like 1.0, 1.9, 2.8, 3.7). In the onChanged callback, using value.toInt() truncates these values (so 2.8 becomes 2), which causes the inconsistent snapping behavior across the range. To get clean integer steps, we should set divisions: 9 or use value instead of value.toInt().

CC @dkwingsmt

Screen.Recording.2026-04-07.at.4.46.45.PM.mov

Fix discrete Slider snapping to wrong value when tapping lower-half t…

As I mentioned above, the behavior is WAI.

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.

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Slider selects the wrong value when tapping on lower-half divisions #184391

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Slider selects the wrong value when tapping on lower-half divisions #184391

Description

Steps to reproduce

Expected results

Actual results

Code sample

Screenshots or Video

Flutter Doctor output

Activity

zoepatterson1231-del commented on Mar 31, 2026

bhpy247 commented on Mar 31, 2026

namitbor-cmd commented on Mar 31, 2026

Mairramer commented on Mar 31, 2026

saurabh-mirajkar commented on Apr 1, 2026

mu7mmd commented on Apr 1, 2026

dkwingsmt commented on Apr 1, 2026

QuncCccccc commented on Apr 7, 2026

QuncCccccc commented on Oct 9, 2026

github-actions commented on Oct 23, 2026

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