diff --git a/readme.md b/readme.md
index 2159fa03..548e9cf3 100644
--- a/readme.md
+++ b/readme.md
@@ -12,12 +12,18 @@
 
 ```ts
 // Install it with `npm i baseroo`
-import { convertBase } from 'baseroo'
+import { convertBase, customAlphabet } from 'baseroo'
 
 const base16Value = '8f.3333333333'
 
 // Works for floating point numbers to a precision of 10 places.
 const base10Value = convertBase(base16Value, 16, 10) // '143.1999999999'
+
+// Supports base conversion using custom alphabet
+const convertBaseWithUserAlphabet = customAlphabet(
+	'0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ+/'
+)
+const base32Value = convertBase(base16Value, 16, 32) // '4f.6cpj6cpj'
 ```
 
 ### Background
diff --git a/src/baseroo.ts b/src/baseroo.ts
index e4ff02de..e3defc08 100644
--- a/src/baseroo.ts
+++ b/src/baseroo.ts
@@ -23,9 +23,6 @@ function bigIntPow(x: bigint, y: bigint): bigint {
 	return x * p2 * p2
 }
 
-export const defaultAlphabet = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ+/'
-const defaultAlphabetRange = defaultAlphabet.split('')
-
 function convertToBase10Integer(integerValue: string, fromAlphabet: string[]): bigint {
 	const fromBase = BigInt(fromAlphabet.length)
 
@@ -76,9 +73,7 @@ function convertFromBase10Fractional(base10Fractional: number, toAlphabet: strin
 	return value
 }
 
-export function convertBase(value: string, fromBase: number, toBase: number): string {
-	const range = defaultAlphabetRange
-
+function convertBaseShim(range: string[], value: string, fromBase: number, toBase: number): string {
 	if (fromBase < 2 || fromBase > range.length) {
 		throw new InvalidBaseError('fromBase', fromBase, range.length)
 	}
@@ -104,3 +99,11 @@ export function convertBase(value: string, fromBase: number, toBase: number): st
 
 	return toBaseSign + toBaseInteger
 }
+
+export function customAlphabet(alphabet: string) {
+	return convertBaseShim.bind(null, alphabet.split(''))
+}
+
+export const defaultAlphabet = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ+/'
+
+export const convertBase = customAlphabet(defaultAlphabet)