diff --git a/package-lock.json b/package-lock.json
index d071a8ed..76470ae0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -16,6 +16,7 @@
         "@fastify/type-provider-typebox": "^2.1.0",
         "@sinclair/typebox": "^0.24.20",
         "@types/node": "^18.13.0",
+        "bignumber.js": "^9.1.1",
         "bitcoinjs-lib": "^6.1.0",
         "env-schema": "^5.2.0",
         "fastify": "^4.3.0",
@@ -2951,6 +2952,14 @@
       "resolved": "https://registry.npmjs.org/bech32/-/bech32-2.0.0.tgz",
       "integrity": "sha512-LcknSilhIGatDAsY1ak2I8VtGaHNhgMSYVxFrGLXv+xLHytaKZKcaUJJUE7qmBr7h33o5YQwP55pMI0xmkpJwg=="
     },
+    "node_modules/bignumber.js": {
+      "version": "9.1.1",
+      "resolved": "https://registry.npmjs.org/bignumber.js/-/bignumber.js-9.1.1.tgz",
+      "integrity": "sha512-pHm4LsMJ6lzgNGVfZHjMoO8sdoRhOzOH4MLmY65Jg70bpxCKu5iOHNJyfF6OyvYw7t8Fpf35RuzUyqnQsj8Vig==",
+      "engines": {
+        "node": "*"
+      }
+    },
     "node_modules/bintrees": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/bintrees/-/bintrees-1.0.2.tgz",
@@ -14840,6 +14849,11 @@
       "resolved": "https://registry.npmjs.org/bech32/-/bech32-2.0.0.tgz",
       "integrity": "sha512-LcknSilhIGatDAsY1ak2I8VtGaHNhgMSYVxFrGLXv+xLHytaKZKcaUJJUE7qmBr7h33o5YQwP55pMI0xmkpJwg=="
     },
+    "bignumber.js": {
+      "version": "9.1.1",
+      "resolved": "https://registry.npmjs.org/bignumber.js/-/bignumber.js-9.1.1.tgz",
+      "integrity": "sha512-pHm4LsMJ6lzgNGVfZHjMoO8sdoRhOzOH4MLmY65Jg70bpxCKu5iOHNJyfF6OyvYw7t8Fpf35RuzUyqnQsj8Vig=="
+    },
     "bintrees": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/bintrees/-/bintrees-1.0.2.tgz",
diff --git a/package.json b/package.json
index 6d6056f6..e5af288d 100644
--- a/package.json
+++ b/package.json
@@ -51,6 +51,7 @@
     "@fastify/type-provider-typebox": "^2.1.0",
     "@sinclair/typebox": "^0.24.20",
     "@types/node": "^18.13.0",
+    "bignumber.js": "^9.1.1",
     "bitcoinjs-lib": "^6.1.0",
     "env-schema": "^5.2.0",
     "fastify": "^4.3.0",
diff --git a/src/api/util/ordinal-satoshi.ts b/src/api/util/ordinal-satoshi.ts
index d1df412a..d09036b6 100644
--- a/src/api/util/ordinal-satoshi.ts
+++ b/src/api/util/ordinal-satoshi.ts
@@ -1,3 +1,5 @@
+import BigNumber from 'bignumber.js';
+
 const HALVING_BLOCKS = 210_000;
 const DIFFICULTY_ADJUST_BLOCKS = 2016;
 const INITIAL_SUBSIDY = 50;
@@ -13,6 +15,10 @@ export enum SatoshiRarity {
   mythic = 'mythic',
 }
 
+/**
+ * Ordinal Satoshi calculator. Mostly translated from the original Rust implementation at
+ * https://github.com/casey/ord/blob/master/src/sat.rs
+ */
 export class OrdinalSatoshi {
   public blockHeight: number;
   public cycle: number;
@@ -75,7 +81,8 @@ export class OrdinalSatoshi {
   }
 
   public get percentile(): string {
-    return `${(this.ordinal / (SAT_SUPPLY - 1)) * 100.0}%`;
+    const percentile = new BigNumber((this.ordinal / (SAT_SUPPLY - 1)) * 100.0);
+    return `${percentile.toFixed()}%`;
   }
 
   public get rarity(): SatoshiRarity {
diff --git a/tests/ordinal-satoshi.test.ts b/tests/ordinal-satoshi.test.ts
index f44406cf..28a14ef9 100644
--- a/tests/ordinal-satoshi.test.ts
+++ b/tests/ordinal-satoshi.test.ts
@@ -80,8 +80,7 @@ describe('OrdinalSatoshi', () => {
     expect(sat.epoch).toBe(0);
     expect(sat.name).toBe('nvtdijuwxdx');
     expect(sat.offset).toBe(200);
-    // TODO: Convert scientific notation to number.
-    // expect(sat.percentile).toBe('0.000000000009523809534285719%');
+    expect(sat.percentile).toBe('0.000000000009523809534285719%');
     expect(sat.period).toBe(0);
     expect(sat.blockHeight).toBe(0);
   });