diff --git a/bin/generate-chapters-length b/bin/generate-chapters-length
new file mode 100755
index 0000000..17f596e
--- /dev/null
+++ b/bin/generate-chapters-length
@@ -0,0 +1,16 @@
+#!/usr/bin/env ruby
+
+##
+# This script generates bindata/chapters-length.json - a JSON file
+# that maps each chapter in The Qur'an to the number of verses
+# a chapter contains.
+
+require "json"
+src = File.join("src", "json", "ar", "%{chapter}.json")
+result = {}
+1.upto(114) do
+  path = format(src, chapter: _1)
+  result[_1] = JSON.parse(File.read(path)).size
+end
+File.write File.join("bindata", "chapters-length.json"),
+           JSON.pretty_generate(result)
diff --git a/bindata/chapters-length.json b/bindata/chapters-length.json
new file mode 100644
index 0000000..a5af22f
--- /dev/null
+++ b/bindata/chapters-length.json
@@ -0,0 +1,116 @@
+{
+  "1": 7,
+  "2": 286,
+  "3": 200,
+  "4": 176,
+  "5": 120,
+  "6": 165,
+  "7": 206,
+  "8": 75,
+  "9": 129,
+  "10": 109,
+  "11": 123,
+  "12": 111,
+  "13": 43,
+  "14": 52,
+  "15": 99,
+  "16": 128,
+  "17": 111,
+  "18": 110,
+  "19": 98,
+  "20": 135,
+  "21": 112,
+  "22": 78,
+  "23": 118,
+  "24": 64,
+  "25": 77,
+  "26": 227,
+  "27": 93,
+  "28": 88,
+  "29": 69,
+  "30": 60,
+  "31": 34,
+  "32": 30,
+  "33": 73,
+  "34": 54,
+  "35": 45,
+  "36": 83,
+  "37": 182,
+  "38": 88,
+  "39": 75,
+  "40": 85,
+  "41": 54,
+  "42": 53,
+  "43": 89,
+  "44": 59,
+  "45": 37,
+  "46": 35,
+  "47": 38,
+  "48": 29,
+  "49": 18,
+  "50": 45,
+  "51": 60,
+  "52": 49,
+  "53": 62,
+  "54": 55,
+  "55": 78,
+  "56": 96,
+  "57": 29,
+  "58": 22,
+  "59": 24,
+  "60": 13,
+  "61": 14,
+  "62": 11,
+  "63": 11,
+  "64": 18,
+  "65": 12,
+  "66": 12,
+  "67": 30,
+  "68": 52,
+  "69": 52,
+  "70": 44,
+  "71": 28,
+  "72": 28,
+  "73": 20,
+  "74": 56,
+  "75": 40,
+  "76": 31,
+  "77": 50,
+  "78": 40,
+  "79": 46,
+  "80": 42,
+  "81": 29,
+  "82": 19,
+  "83": 36,
+  "84": 25,
+  "85": 22,
+  "86": 17,
+  "87": 19,
+  "88": 26,
+  "89": 30,
+  "90": 20,
+  "91": 15,
+  "92": 21,
+  "93": 11,
+  "94": 8,
+  "95": 8,
+  "96": 19,
+  "97": 5,
+  "98": 8,
+  "99": 8,
+  "100": 11,
+  "101": 11,
+  "102": 8,
+  "103": 3,
+  "104": 9,
+  "105": 5,
+  "106": 4,
+  "107": 7,
+  "108": 3,
+  "109": 6,
+  "110": 3,
+  "111": 5,
+  "112": 4,
+  "113": 5,
+  "114": 6
+}
\ No newline at end of file