diff --git a/src/confscreen.cpp b/src/confscreen.cpp
index 8f01108..e518e1b 100644
--- a/src/confscreen.cpp
+++ b/src/confscreen.cpp
@@ -186,10 +186,10 @@ void TextWindow::ShowConfiguration(void) {
     }
 
     Printf(false, "");
-    Printf(false, "%Ft chord tolerance (in screen pixels)%E");
-    Printf(false, "%Ba   %@ %Fl%Ll%f%D[change]%E; now %d triangles",
+    Printf(false, "%Ft chord tolerance (in percents)%E");
+    Printf(false, "%Ba   %@ %% %Fl%Ll%f%D[change]%E; %@ mm, %d triangles",
         SS.chordTol,
-        &ScreenChangeChordTolerance, 0,
+        &ScreenChangeChordTolerance, 0, SS.chordTolCalculated,
         SK.GetGroup(SS.GW.activeGroup)->displayMesh.l.n);
     Printf(false, "%Ft max piecewise linear segments%E");
     Printf(false, "%Ba   %d %Fl%Ll%f[change]%E",
diff --git a/src/generate.cpp b/src/generate.cpp
index 6cd3579..4e248b5 100644
--- a/src/generate.cpp
+++ b/src/generate.cpp
@@ -174,7 +174,7 @@ void SolveSpaceUI::GenerateAll(GenerateType type, bool andFindFree) {
     }
 }
 
-void SolveSpaceUI::GenerateAll(int first, int last, bool andFindFree) {
+void SolveSpaceUI::GenerateAll(int first, int last, bool andFindFree, bool genForBBox) {
     int i, j;
 
     // generate until active group
@@ -183,6 +183,16 @@ void SolveSpaceUI::GenerateAll(int first, int last, bool andFindFree) {
         if(last == -1) last = INT_MAX;
     }
 
+    // If we're generating entities for display, first we need to find
+    // the bounding box to turn relative chord tolerance to absolute.
+    if(!SS.exportMode && !genForBBox) {
+        GenerateAll(first, last, false, true);
+        BBox box = SK.CalculateEntityBBox(false);
+        Vector size = box.maxp.Minus(box.minp);
+        double maxSize = std::max({ size.x, size.y, size.z });
+        chordTolCalculated = maxSize * chordTol / 100.0;
+    }
+
     // Remove any requests or constraints that refer to a nonexistent
     // group; can check those immediately, since we know what the list
     // of groups should be.
@@ -275,10 +285,13 @@ void SolveSpaceUI::GenerateAll(int first, int last, bool andFindFree) {
             if(i >= first && i <= last) {
                 // The group falls inside the range, so really solve it,
                 // and then regenerate the mesh based on the solved stuff.
-                SolveGroup(g->h, andFindFree);
-                g->GenerateLoops();
-                g->GenerateShellAndMesh();
-                g->clean = true;
+                if(genForBBox) {
+                    SolveGroup(g->h, andFindFree);
+                } else {
+                    g->GenerateLoops();
+                    g->GenerateShellAndMesh();
+                    g->clean = true;
+                }
             } else {
                 // The group falls outside the range, so just assume that
                 // it's good wherever we left it. The mesh is unchanged,
@@ -364,7 +377,7 @@ pruned:
     SK.param.Clear();
     prev.MoveSelfInto(&(SK.param));
     // Try again
-    GenerateAll(first, last);
+    GenerateAll(first, last, andFindFree, genForBBox);
 }
 
 void SolveSpaceUI::ForceReferences(void) {
diff --git a/src/solvespace.cpp b/src/solvespace.cpp
index fdc3d45..e4b646c 100644
--- a/src/solvespace.cpp
+++ b/src/solvespace.cpp
@@ -39,7 +39,7 @@ void SolveSpaceUI::Init() {
 
     exportMode = false;
     // Chord tolerance
-    chordTol = CnfThawFloat(2.0f, "ChordTolerance");
+    chordTol = CnfThawFloat(0.5f, "ChordTolerancePct");
     // Max pwl segments to generate
     maxSegments = CnfThawInt(10, "MaxSegments");
     // Chord tolerance
@@ -160,7 +160,7 @@ void SolveSpaceUI::Exit(void) {
     CnfFreezeFloat((float)lightDir[1].y, "LightDir_1_Up");
     CnfFreezeFloat((float)lightDir[1].z, "LightDir_1_Forward");
     // Chord tolerance
-    CnfFreezeFloat((float)chordTol, "ChordTolerance");
+    CnfFreezeFloat((float)chordTol, "ChordTolerancePct");
     // Max pwl segments to generate
     CnfFreezeInt((uint32_t)maxSegments, "MaxSegments");
     // Export Chord tolerance
@@ -270,7 +270,7 @@ double SolveSpaceUI::StringToMm(const std::string &str) {
 }
 double SolveSpaceUI::ChordTolMm(void) {
     if(exportMode) return ExportChordTolMm();
-    return chordTol / GW.scale;
+    return chordTolCalculated;
 }
 double SolveSpaceUI::ExportChordTolMm(void) {
     return exportChordTol / exportScale;
diff --git a/src/solvespace.h b/src/solvespace.h
index 4ee1775..c7e251d 100644
--- a/src/solvespace.h
+++ b/src/solvespace.h
@@ -753,6 +753,7 @@ public:
     double   lightIntensity[2];
     double   ambientIntensity;
     double   chordTol;
+    double   chordTolCalculated;
     int      maxSegments;
     double   exportChordTol;
     int      exportMaxSegments;
@@ -941,7 +942,7 @@ public:
     
     void GenerateAll(GenerateType type, bool andFindFree = false);
     void GenerateAll(void);
-    void GenerateAll(int first, int last, bool andFindFree=false);
+    void GenerateAll(int first, int last, bool andFindFree = false, bool genForBBox = false);
     void SolveGroup(hGroup hg, bool andFindFree);
     void MarkDraggedParams(void);
     void ForceReferences(void);