diff --git a/package.json b/package.json
index e4db2f0a4..bc9f37e5a 100644
--- a/package.json
+++ b/package.json
@@ -82,6 +82,7 @@
         "@sentry/tracing": "^6.18.2",
         "@tabler/icons": "1.54.0",
         "@tippyjs/react": "4.2.5",
+        "bignumber.js": "^9.0.2",
         "capacitor-voice-recorder": "2.1.0",
         "chokidar": "3.5.1",
         "chrono-node": "2.2.4",
diff --git a/src/main/frontend/extensions/calc.cljc b/src/main/frontend/extensions/calc.cljc
index bba3a9bf5..afe2c06af 100644
--- a/src/main/frontend/extensions/calc.cljc
+++ b/src/main/frontend/extensions/calc.cljc
@@ -3,6 +3,9 @@
   (:require [clojure.edn :as edn]
             [clojure.string :as str]
             [frontend.util :as util]
+
+            [bignumber.js :as bn]
+
             #?(:clj [clojure.java.io :as io])
             #?(:cljs [shadow.resource :as rc])
             #?(:cljs [rum.core :as rum])
@@ -24,17 +27,19 @@
 
 (defn new-env [] (atom {}))
 
+;; TODO: Set DECIMAL_PLACES https://mikemcl.github.io/bignumber.js/#decimal-places
+
 (defn eval* [env ast]
   (insta/transform
-   {:number     (comp edn/read-string #(str/replace % "," ""))
+   {:number     (comp bn/BigNumber #(str/replace % "," ""))
     :percent    (fn percent [a] (/ a 100.00))
     :scientific edn/read-string
     :negterm    (fn neg [a] (- a))
     :expr       identity
-    :add        +
-    :sub        -
-    :mul        *
-    :div        /
+    :add        (fn add [a b] (-> a (.plus b)))
+    :sub        (fn sub [a b] (-> a (.minus b)))
+    :mul        (fn mul [a b] (-> a (.multipliedBy b)))
+    :div        (fn div [a b] (-> a (.dividedBy b)))
     :pow        (fn pow [a b]
                   #?(:clj (java.lang.Math/pow a b) :cljs (js/Math.pow a b)))
     :log        (fn log [a]
@@ -101,4 +106,4 @@
            [:span (cond
                     (nil? line)           ""
                     (failure? line) "?"
-                    :else                 line)]])])))
+                    :else                 (str line))]])])))
diff --git a/yarn.lock b/yarn.lock
index 094b84e6f..9b28e884a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1651,6 +1651,11 @@ big-integer@1.6.x:
   resolved "https://registry.yarnpkg.com/big-integer/-/big-integer-1.6.51.tgz#0df92a5d9880560d3ff2d5fd20245c889d130686"
   integrity sha512-GPEid2Y9QU1Exl1rpO9B2IPJGHPSupF5GnVIP0blYvNOMer2bTvSWs1jGOUg04hTmu67nmLsQ9TBo1puaotBHg==
 
+bignumber.js@^9.0.2:
+  version "9.0.2"
+  resolved "https://registry.yarnpkg.com/bignumber.js/-/bignumber.js-9.0.2.tgz#71c6c6bed38de64e24a65ebe16cfcf23ae693673"
+  integrity sha512-GAcQvbpsM0pUb0zw1EI0KhQEZ+lRwR5fYaAp3vPOYuP7aDvGy6cVN6XHLauvF8SOga2y0dcLcjt3iQDTSEliyw==
+
 binary-extensions@^1.0.0:
   version "1.13.1"
   resolved "https://registry.yarnpkg.com/binary-extensions/-/binary-extensions-1.13.1.tgz#598afe54755b2868a5330d2aff9d4ebb53209b65"