diff --git a/src/config.js b/src/config.js
index 40b70ddf..04ccb85c 100644
--- a/src/config.js
+++ b/src/config.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const { release } = require('./package.json');
+const Util = require('./lib/Util');
 
 module.exports.RELEASE = release;
 module.exports.PORT = process.env.PORT || '51821';
@@ -15,14 +16,16 @@ module.exports.WG_CONFIG_PORT = process.env.WG_CONFIG_PORT || process.env.WG_POR
 module.exports.WG_MTU = process.env.WG_MTU || null;
 module.exports.WG_PERSISTENT_KEEPALIVE = process.env.WG_PERSISTENT_KEEPALIVE || '0';
 module.exports.WG_DEFAULT_ADDRESS = process.env.WG_DEFAULT_ADDRESS || '10.8.0.x';
+module.exports.WG_CIDR = 40 - (module.exports.WG_DEFAULT_ADDRESS.split('x').length * 8);
 module.exports.WG_DEFAULT_DNS = typeof process.env.WG_DEFAULT_DNS === 'string'
   ? process.env.WG_DEFAULT_DNS
   : '1.1.1.1';
+
 module.exports.WG_ALLOWED_IPS = process.env.WG_ALLOWED_IPS || '0.0.0.0/0, ::/0';
 
 module.exports.WG_PRE_UP = process.env.WG_PRE_UP || '';
 module.exports.WG_POST_UP = process.env.WG_POST_UP || `
-iptables -t nat -A POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS.replace('x', '0')}/24 -o ${module.exports.WG_DEVICE} -j MASQUERADE;
+iptables -t nat -A POSTROUTING -s ${Util.replaceAll(module.exports.WG_DEFAULT_ADDRESS, 'x', '0')}/${module.exports.WG_CIDR} -o ${module.exports.WG_DEVICE} -j MASQUERADE;
 iptables -A INPUT -p udp -m udp --dport ${module.exports.WG_PORT} -j ACCEPT;
 iptables -A FORWARD -i wg0 -j ACCEPT;
 iptables -A FORWARD -o wg0 -j ACCEPT;
@@ -30,7 +33,7 @@ iptables -A FORWARD -o wg0 -j ACCEPT;
 
 module.exports.WG_PRE_DOWN = process.env.WG_PRE_DOWN || '';
 module.exports.WG_POST_DOWN = process.env.WG_POST_DOWN || `
-iptables -t nat -D POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS.replace('x', '0')}/24 -o ${module.exports.WG_DEVICE} -j MASQUERADE;
+iptables -t nat -D POSTROUTING -s ${Util.replaceAll(module.exports.WG_DEFAULT_ADDRESS, 'x', '0')}/${module.exports.WG_CIDR} -o ${module.exports.WG_DEVICE} -j MASQUERADE;
 iptables -D INPUT -p udp -m udp --dport ${module.exports.WG_PORT} -j ACCEPT;
 iptables -D FORWARD -i wg0 -j ACCEPT;
 iptables -D FORWARD -o wg0 -j ACCEPT;
diff --git a/src/lib/Util.js b/src/lib/Util.js
index cc6e89c2..4cf6d0e3 100644
--- a/src/lib/Util.js
+++ b/src/lib/Util.js
@@ -77,4 +77,8 @@ module.exports = class Util {
     });
   }
 
+  static replaceAll(str, match, substitute) {
+    return str.split(match).join(substitute);
+  }
+
 };
diff --git a/src/lib/WireGuard.js b/src/lib/WireGuard.js
index d4f32c5f..d0f58a94 100644
--- a/src/lib/WireGuard.js
+++ b/src/lib/WireGuard.js
@@ -17,6 +17,7 @@ const {
   WG_MTU,
   WG_DEFAULT_DNS,
   WG_DEFAULT_ADDRESS,
+  WG_CIDR,
   WG_PERSISTENT_KEEPALIVE,
   WG_ALLOWED_IPS,
   WG_PRE_UP,
@@ -45,7 +46,7 @@ module.exports = class WireGuard {
           const publicKey = await Util.exec(`echo ${privateKey} | wg pubkey`, {
             log: 'echo ***hidden*** | wg pubkey',
           });
-          const address = WG_DEFAULT_ADDRESS.replace('x', '1');
+          const address = Util.replaceAll(WG_DEFAULT_ADDRESS, "x", "1");
 
           config = {
             server: {
@@ -87,6 +88,7 @@ module.exports = class WireGuard {
   }
 
   async __saveConfig(config) {
+    
     let result = `
 # Note: Do not edit this file directly.
 # Your changes will be overwritten!
@@ -94,7 +96,7 @@ module.exports = class WireGuard {
 # Server
 [Interface]
 PrivateKey = ${config.server.privateKey}
-Address = ${config.server.address}/24
+Address = ${config.server.address}/${WG_CIDR}
 ListenPort = ${WG_PORT}
 PreUp = ${WG_PRE_UP}
 PostUp = ${WG_POST_UP}
@@ -199,7 +201,7 @@ ${client.preSharedKey ? `PresharedKey = ${client.preSharedKey}\n` : ''
     return `
 [Interface]
 PrivateKey = ${client.privateKey ? `${client.privateKey}` : 'REPLACE_ME'}
-Address = ${client.address}/24
+Address = ${client.address}/${WG_CIDR}
 ${WG_DEFAULT_DNS ? `DNS = ${WG_DEFAULT_DNS}\n` : ''}\
 ${WG_MTU ? `MTU = ${WG_MTU}\n` : ''}\
 
@@ -230,18 +232,39 @@ Endpoint = ${WG_HOST}:${WG_CONFIG_PORT}`;
     const publicKey = await Util.exec(`echo ${privateKey} | wg pubkey`);
     const preSharedKey = await Util.exec('wg genpsk');
 
-    // Calculate next IP
-    let address;
-    for (let i = 2; i < 255; i++) {
+    /* ------ compute next IP address ------*/
+    const recursiveFindIpAdress = (o1, o2, o3, o4) => {
+      if (o4 > 255) {
+        if (WG_CIDR === 24)
+          return null;
+        o3++;
+        o4 = 0;
+      }
+      if (o3 > 255) {
+        if (WG_CIDR === 16)
+          return null;
+        o2++;
+        o3 = 0;
+      }
+      if (o2 > 255) {
+        if (WG_CIDR === 8)
+          return null;
+        o1++;
+        o2 = 0;
+      }
       const client = Object.values(config.clients).find((client) => {
-        return client.address === WG_DEFAULT_ADDRESS.replace('x', i);
+        return client.address === `${o1}.${o2}.${o3}.${o4}`;
       });
-
       if (!client) {
-        address = WG_DEFAULT_ADDRESS.replace('x', i);
-        break;
+        return `${o1}.${o2}.${o3}.${o4}`;
       }
+      return recursiveFindIpAdress(o1, o2, o3, o4 + 1);
     }
+    const [o1, o2, o3, o4] = WG_DEFAULT_ADDRESS.split('.').map(i => (
+      i === 'x' ? 0 : parseInt(i, 10)
+    ));
+    const address = recursiveFindIpAdress(o1, o2, o3, 2);
+    /*------ end compute next IP address ------*/
 
     if (!address) {
       throw new Error('Maximum number of clients reached.');