diff --git a/module/actor-sheet.js b/module/actor-sheet.js
index dd5add0..e8a153a 100644
--- a/module/actor-sheet.js
+++ b/module/actor-sheet.js
@@ -21,7 +21,7 @@ export class SimpleActorSheet extends ActorSheet {
   /** @override */
   getData() {
     const data = super.getData();
-    data.dtypes = ["String", "Number", "Boolean"];
+    data.dtypes = ["String", "Number", "Boolean", "Formula"];
     for ( let attr of Object.values(data.data.attributes) ) {
       attr.isCheckbox = attr.dtype === "Boolean";
     }
@@ -112,7 +112,7 @@ export class SimpleActorSheet extends ActorSheet {
       obj[k] = v;
       return obj;
     }, {});
-    
+
     // Remove attributes which are no longer used
     for ( let k of Object.keys(this.object.data.data.attributes) ) {
       if ( !attributes.hasOwnProperty(k) ) attributes[`-=${k}`] = null;
@@ -123,7 +123,7 @@ export class SimpleActorSheet extends ActorSheet {
       obj[e[0]] = e[1];
       return obj;
     }, {_id: this.object._id, "data.attributes": attributes});
-    
+
     // Update the Actor
     return this.object.update(formData);
   }
diff --git a/module/actor.js b/module/actor.js
index 0f85c7f..ae4a321 100644
--- a/module/actor.js
+++ b/module/actor.js
@@ -8,28 +8,119 @@ export class SimpleActor extends Actor {
   getRollData() {
     const data = super.getRollData();
     const shorthand = game.settings.get("worldbuilding", "macroShorthand");
+    const formulaAttributes = [];
 
     // Re-map all attributes onto the base roll data
     if ( !!shorthand ) {
       for ( let [k, v] of Object.entries(data.attributes) ) {
-        if ( !(k in data) ) data[k] = v.value;
+        if ( !(k in data) ) {
+          data[k] = v.value;
+          // Make an array of formula attributes for later reference.
+          if ( v.dtype == "Formula" ) formulaAttributes.push(k);
+        }
       }
       delete data.attributes;
     }
+    // Handle formula attributes when the short syntax is disabled.
+    else {
+      for ( let [k, v] of Object.entries(data.attributes) ) {
+        // Make an array of formula attributes for later reference.
+        if ( v.dtype == "Formula" ) formulaAttributes.push(k);
+      }
+    }
 
     // Map all items data using their slugified names
     data.items = this.data.items.reduce((obj, i) => {
       let key = i.name.slugify({strict: true});
       let itemData = duplicate(i.data);
+      const itemAttributes = [];
+
+      // Add items as shorthand.
       if ( !!shorthand ) {
         for ( let [k, v] of Object.entries(itemData.attributes) ) {
-          if ( !(k in itemData) ) itemData[k] = v.value;
+          if ( !(k in itemData) ) {
+            itemData[k] = v.value;
+            if ( v.dtype == "Formula" ) itemAttributes.push(k);
+          }
         }
         delete itemData["attributes"];
       }
+      // Add formula items when shorthand isn't enabled.
+      else {
+        for ( let [k, v] of Object.entries(itemData.attributes) ) {
+          if ( v.dtype == "Formula" ) itemAttributes.push(k);
+        }
+      }
+
+      // Evaluate formula attributes after all other attributes have been handled.
+      for ( let k of itemAttributes ) {
+        // Shorthand.
+        if ( !!shorthand ) {
+          if ( itemData[k] ) {
+            itemData[k] = this._replaceData(itemData[k], itemData, data);
+          }
+        }
+        // Full syntax.
+        else {
+          if ( itemData.attributes[k].value ) {
+            itemData.attributes[k].value = this._replaceData(itemData.attributes[k].value, itemData, data);
+          }
+        }
+      }
+
       obj[key] = itemData;
       return obj;
     }, {});
+
+    // Evaluate formula attributes after all other attributes have been handled,
+    // including items.
+    for ( let k of formulaAttributes ) {
+      // Shorthand.
+      if ( !!shorthand ) {
+        if ( data[k] ) {
+          data[k] = this._replaceData(data[k], data);
+        }
+      }
+      // Full syntax.
+      else {
+        if ( data.attributes[k].value ) {
+          data.attributes[k].value = this._replaceData(data.attributes[k].value, data);
+        }
+      }
+    }
+
     return data;
   }
+
+  /**
+   * Replace referenced data attributes in the roll formula with the syntax `@attr` with the corresponding key from
+   * the provided `data` object.
+   * @param {String} formula    The original formula within which to replace.
+   * @return {String} The formula with attributes replaced with values.
+   */
+  _replaceData(formula, dataPrimary, dataSecondary = null) {
+    // Exit early if the formula is invalid.
+    if ( typeof formula != "string" ) {
+      return 0;
+    }
+
+    // Replace attributes with their numeric equivalents.
+    let dataRgx = new RegExp(/@([a-z.0-9_\-]+)/gi);
+    let rollFormula = formula.replace(dataRgx, (match, term) => {
+      // Try the primary data source first (ex: actor, item).
+      let value = getProperty(dataPrimary, term);
+      if ( value ) {
+        return String(value).trim();
+      }
+      // Try the secondary data source next (ex: actor that owns item);
+      else if (dataSecondary) {
+        value = getProperty(dataSecondary, term);
+        return value ? String(value).trim() : "0";
+      }
+      // Otherwise, return 0.
+      return "0";
+    });
+
+    return rollFormula;
+  }
 }
diff --git a/module/item-sheet.js b/module/item-sheet.js
index 8d378e1..a743a5f 100644
--- a/module/item-sheet.js
+++ b/module/item-sheet.js
@@ -20,7 +20,7 @@ export class SimpleItemSheet extends ItemSheet {
   /** @override */
   getData() {
     const data = super.getData();
-    data.dtypes = ["String", "Number", "Boolean"];
+    data.dtypes = ["String", "Number", "Boolean", "Formula"];
     for ( let attr of Object.values(data.data.attributes) ) {
       attr.isCheckbox = attr.dtype === "Boolean";
     }
@@ -97,7 +97,7 @@ export class SimpleItemSheet extends ItemSheet {
       obj[k] = v;
       return obj;
     }, {});
-    
+
     // Remove attributes which are no longer used
     for ( let k of Object.keys(this.object.data.data.attributes) ) {
       if ( !attributes.hasOwnProperty(k) ) attributes[`-=${k}`] = null;