diff --git a/crates/ui-egui/src/widgets.rs b/crates/ui-egui/src/widgets.rs
index 2e139d013..c74a78a0f 100644
--- a/crates/ui-egui/src/widgets.rs
+++ b/crates/ui-egui/src/widgets.rs
@@ -57,7 +57,7 @@ pub use numeric::{
     spin_field_auto, spin_field_auto_named, spin_field_named, spin_field_stops_named, spin_kerning, spin_plain, spin_plain_named,
 };
 #[cfg(test)]
-use numeric::{decimal_point, share_of, spinner_step, step_through, step_to_multiple, within_a_millionth};
+use numeric::{decimal_point, field_number, share_of, spinner_step, step_through, step_to_multiple, within_a_millionth};
 pub use panel_chrome::{bottom_bar, layout_button, list_box, orientation_button, tab_bar};
 pub(crate) use text::{
     arm_field_focus, dialog_focus_flag, dialog_reject_commit_flag, disarm_field_focus, enter_modifiers, focus_field, own_field_shift_enter,
@@ -464,6 +464,30 @@ mod decimal_point_tests {
     }
 }
 
+#[cfg(test)]
+mod field_number_tests {
+    use super::*;
+
+    /// Kerning drops one pair of parentheses around its whole text, so its automatic value `(12)`
+    /// reads as 12. Parentheses inside the text are refused rather than dropped, which would read
+    /// `(10+5)*2` as `10+5*2`, and fields without the Kerning flag refuse parentheses too.
+    #[test]
+    fn only_kerning_drops_one_pair_of_parentheses_around_the_text() {
+        assert_eq!(field_number("(12)", "", true), Some(12.0));
+        assert_eq!(field_number(" (-25) ", "", true), Some(-25.0));
+        assert_eq!(field_number("(10+5)", "", true), Some(15.0));
+        assert_eq!(field_number("12", "", true), Some(12.0));
+        for text in ["(10+5)*2", "2*(10+5)", "(10)+(5)", "((12))", "(12", "12)"] {
+            assert_eq!(field_number(text, "", true), None, "{text}");
+        }
+        for text in ["(12)", "(10+5)*2"] {
+            assert_eq!(field_number(text, "", false), None, "{text} without the Kerning flag");
+        }
+        assert_eq!(field_number("45*2°", "°", false), Some(90.0));
+        assert_eq!(field_number("50% / 2", "%", false), Some(25.0));
+    }
+}
+
 #[cfg(test)]
 mod menu_room_tests {
     use super::*;
diff --git a/crates/ui-egui/src/widgets/numeric.rs b/crates/ui-egui/src/widgets/numeric.rs
index 91cd18eeb..56ace75b8 100644
--- a/crates/ui-egui/src/widgets/numeric.rs
+++ b/crates/ui-egui/src/widgets/numeric.rs
@@ -454,13 +454,7 @@ fn bounded_field(
     let armed = take_armed_focus(ui, &id);
     let id = id_with(ui.scope_id(), id);
     let show = |value: f64| field_text(value, suffix, decimals);
-    // The suffix (and %, °) may follow any operand: `45*2°`, `50% / 2`.
-    let read = |buf: &str| {
-        let suffix = suffix.trim();
-        let buf = decimal_point(buf);
-        let bare = if suffix.is_empty() { buf.to_string() } else { buf.replace(suffix, "") };
-        vectorcraft_doc::parse_number(&bare.replace(['%', '°', '(', ')'], ""))
-    };
+    let read = |buf: &str| field_number(buf, suffix, parentheses);
     let shown = value.map(|v| if parentheses { format!("({})", show(v)) } else { show(v) }).unwrap_or_default();
     take_dialog_focus(ui, id, &shown);
     if armed {
@@ -491,6 +485,21 @@ fn bounded_field(
     }
 }
 
+/// The number text typed into a [`bounded_field`] with `suffix` reads as. The suffix, `%` and `°`
+/// may follow any operand: `45*2°`, `50% / 2`. With `parentheses` (Kerning, which shows its
+/// automatic value as `(12)`), one pair of parentheses around the whole text is dropped first, so
+/// `(12)` reads as 12. Any other parentheses are refused: `(10+5)*2` reads as nothing, not as
+/// `10+5*2`.
+pub(super) fn field_number(buf: &str, suffix: &str, parentheses: bool) -> Option<f64> {
+    let suffix = suffix.trim();
+    let buf = decimal_point(buf);
+    let bare = if suffix.is_empty() { buf.to_string() } else { buf.replace(suffix, "") };
+    let bare = bare.replace(['%', '°'], "");
+    let bare = bare.trim();
+    let bare = if parentheses { bare.strip_prefix('(').and_then(|b| b.strip_suffix(')')).unwrap_or(bare) } else { bare };
+    vectorcraft_doc::parse_number(bare)
+}
+
 /// The text [`plain_field`] shows for `value`: at most `decimals` places, without trailing zeros,
 /// then `suffix`.
 pub(super) fn field_text(value: f64, suffix: &str, decimals: usize) -> String {