diff --git a/macrovision.js b/macrovision.js
index ea535c2c..1114322f 100644
--- a/macrovision.js
+++ b/macrovision.js
@@ -703,10 +703,26 @@ function drawRulers() {
     ctx.scale(deviceScale, deviceScale);
     
     rulers.concat(currentRuler ? [currentRuler] : []).forEach(rulerDef => {
+        let x0 = rulerDef.x0;
+        let y0 = rulerDef.y0;
+        let x1 = rulerDef.x1;
+        let y1 = rulerDef.y1;
+        if (rulerDef.entityKey !== null) {
+            const entity = entities[rulerDef.entityKey]
+            const entityElement = document.querySelector("#entity-" + rulerDef.entityKey)
+            x0 *= entity.scale;
+            y0 *= entity.scale;
+            x1 *= entity.scale;
+            y1 *= entity.scale;
+            x0 += parseFloat(entityElement.dataset.x)
+            x1 += parseFloat(entityElement.dataset.x)
+            y0 += parseFloat(entityElement.dataset.y)
+            y1 += parseFloat(entityElement.dataset.y)
+        }
         ctx.save();
         ctx.beginPath();
-        const start = pos2pix({x: rulerDef.x0, y: rulerDef.y0});
-        const end = pos2pix({x: rulerDef.x1, y: rulerDef.y1});
+        const start = pos2pix({x: x0, y: y0});
+        const end = pos2pix({x: x1, y: y1});
         ctx.moveTo(start.x, start.y);
         ctx.lineTo(end.x, end.y);
         ctx.lineWidth = 5;
@@ -728,7 +744,7 @@ function drawRulers() {
         const offsetX = Math.cos(angle + Math.PI/2);
         const offsetY = Math.sin(angle + Math.PI/2);
         
-        const distance = Math.sqrt(Math.pow(rulerDef.y1 - rulerDef.y0, 2) + Math.pow(rulerDef.x1 - rulerDef.x0, 2));
+        const distance = Math.sqrt(Math.pow(y1 - y0, 2) + Math.pow(x1 - x0, 2));
         const distanceInUnits = math.unit(distance, "meters").to(document.querySelector("#options-height-unit").value);
         const textSize = ctx.measureText(distanceInUnits.format({ precision: 3}));
         ctx.fillText(distanceInUnits.format({ precision: 3}), -offsetX * 10 - textSize.width / 2, -offsetY*10);
@@ -1405,6 +1421,9 @@ function clickUp(e) {
 }
 
 function deselect(e) {
+    if (rulerMode) {
+        return;
+    }
     if (e !== undefined && e.which != 1) {
         return;
     }
@@ -2681,6 +2700,18 @@ const settingsData = {
             }
         }
     },
+    "attach-rulers": {
+        name: "Attach Rulers",
+        desc: "Rulers will attach to the currently-selected entity, moving around with it.",
+        type: "toggle",
+        default: true,
+        get value() {
+            return config.rulersStick;
+        },
+        set value(param) {
+            config.rulersStick = param;
+        }
+    },
     "units": {
         name: "Default Units",
         desc: "Which kind of unit to use by default",
@@ -3074,6 +3105,21 @@ function selectNewUnit() {
     unitSelector.dataset.oldUnit = unitSelector.value;
 }
 
+// given a world position, return the position relative to the entity at normal scale
+function entityRelativePosition(pos, entityElement) {
+    const entity = entities[entityElement.dataset.key]
+    const x = parseFloat(entityElement.dataset.x)
+    const y = parseFloat(entityElement.dataset.y)
+
+    pos.x /= entity.scale
+    pos.y /= entity.scale
+
+    pos.x -= x
+    pos.y -= y
+
+    return pos
+}
+
 document.addEventListener("DOMContentLoaded", () => {
     prepareMenu();
     prepareEntities();
@@ -3346,8 +3392,16 @@ document.addEventListener("DOMContentLoaded", () => {
         if (e.which == 1 && rulerMode) {
             let entX = document.querySelector("#entities").getBoundingClientRect().x;
             let entY = document.querySelector("#entities").getBoundingClientRect().y;
-            const pos = pix2pos({ x: e.clientX - entX, y: e.clientY - entY });
-            currentRuler = { x0: pos.x, y0: pos.y, x1: pos.y, y1: pos.y };
+            let pos = pix2pos({ x: e.clientX - entX, y: e.clientY - entY });
+
+            if (config.rulersStick && selected) {
+                pos = entityRelativePosition(pos, selected)
+            }
+            currentRuler = { x0: pos.x, y0: pos.y, x1: pos.y, y1: pos.y, entityKey: null };
+
+            if (config.rulersStick && selected) {
+                currentRuler.entityKey = selected.dataset.key
+            }
         }
     });
     document.querySelector("#world").addEventListener("mouseup", e => {
@@ -3363,8 +3417,15 @@ document.addEventListener("DOMContentLoaded", () => {
         if (rulerMode) {
             let entX = document.querySelector("#entities").getBoundingClientRect().x;
             let entY = document.querySelector("#entities").getBoundingClientRect().y;
-            const pos = pix2pos({ x: e.touches[0].clientX - entX, y: e.touches[0].clientY - entY });
-            currentRuler = { x0: pos.x, y0: pos.y, x1: pos.y, y1: pos.y };
+            let pos = pix2pos({ x: e.touches[0].clientX - entX, y: e.touches[0].clientY - entY });
+
+            if (config.rulersStick && selected) {
+                pos = entityRelativePosition(pos, selected)
+            }
+            currentRuler = { x0: pos.x, y0: pos.y, x1: pos.y, y1: pos.y, entityKey: null };
+            if (config.rulersStick && selected) {
+                currentRuler.entityKey = selected.dataset.key
+            }
         }
     });
     document.querySelector("#world").addEventListener("touchend", e => {
@@ -4442,6 +4503,10 @@ document.addEventListener("mousemove", (e) => {
         let entX = document.querySelector("#entities").getBoundingClientRect().x;
         let entY = document.querySelector("#entities").getBoundingClientRect().y;
         let position = pix2pos({ x: e.clientX - entX, y: e.clientY - entY });
+
+        if (config.rulersStick && selected) {
+            position = entityRelativePosition(position, selected)
+        }
         currentRuler.x1 = position.x;
         currentRuler.y1 = position.y;
     }
@@ -4453,6 +4518,9 @@ document.addEventListener("touchmove", (e) => {
         let entX = document.querySelector("#entities").getBoundingClientRect().x;
         let entY = document.querySelector("#entities").getBoundingClientRect().y;
         let position = pix2pos({ x: e.touches[0].clientX - entX, y: e.touches[0].clientY - entY });
+        if (config.rulersStick && selected) {
+            position = entityRelativePosition(position, selected)
+        }
         currentRuler.x1 = position.x;
         currentRuler.y1 = position.y;
     }