diff --git a/backend/src/api/blocks.ts b/backend/src/api/blocks.ts
index fbbe48061..e4e16af3d 100644
--- a/backend/src/api/blocks.ts
+++ b/backend/src/api/blocks.ts
@@ -2,6 +2,7 @@ const config = require('../../mempool-config.json');
 import bitcoinApi from './bitcoin/electrs-api';
 import memPool from './mempool';
 import { Block, TransactionExtended } from '../interfaces';
+import { Common } from './common';
 
 class Blocks {
   private blocks: Block[] = [];
@@ -73,8 +74,8 @@ class Blocks {
 
         block.reward = transactions[0].vout.reduce((acc, curr) => acc + curr.value, 0);
         transactions.sort((a, b) => b.feePerVsize - a.feePerVsize);
-        block.medianFee = transactions.length > 1 ? this.median(transactions.map((tx) => tx.feePerVsize)) : 0;
-        block.feeRange = transactions.length > 1 ? this.getFeesInRange(transactions, 8) : [0, 0];
+        block.medianFee = transactions.length > 1 ? Common.median(transactions.map((tx) => tx.feePerVsize)) : 0;
+        block.feeRange = transactions.length > 1 ? Common.getFeesInRange(transactions, 8) : [0, 0];
         block.coinbaseTx = transactions[0];
 
         this.blocks.push(block);
@@ -89,31 +90,6 @@ class Blocks {
       console.log('updateBlocks error', err);
     }
   }
-
-  private median(numbers: number[]) {
-    let medianNr = 0;
-    const numsLen = numbers.length;
-    if (numsLen % 2 === 0) {
-        medianNr = (numbers[numsLen / 2 - 1] + numbers[numsLen / 2]) / 2;
-    } else {
-        medianNr = numbers[(numsLen - 1) / 2];
-    }
-    return medianNr;
-  }
-
-  private getFeesInRange(transactions: any[], rangeLength: number) {
-    const arr = [transactions[transactions.length - 1].feePerVsize];
-    const chunk = 1 / (rangeLength - 1);
-    let itemsToAdd = rangeLength - 2;
-
-    while (itemsToAdd > 0) {
-      arr.push(transactions[Math.floor(transactions.length * chunk * itemsToAdd)].feePerVsize);
-      itemsToAdd--;
-    }
-
-    arr.push(transactions[1].feePerVsize);
-    return arr;
-  }
 }
 
 export default new Blocks();
diff --git a/backend/src/api/common.ts b/backend/src/api/common.ts
new file mode 100644
index 000000000..2d63804f7
--- /dev/null
+++ b/backend/src/api/common.ts
@@ -0,0 +1,28 @@
+import { TransactionExtended } from '../interfaces';
+
+export class Common {
+  static median(numbers: number[]) {
+    let medianNr = 0;
+    const numsLen = numbers.length;
+    if (numsLen % 2 === 0) {
+        medianNr = (numbers[numsLen / 2 - 1] + numbers[numsLen / 2]) / 2;
+    } else {
+        medianNr = numbers[(numsLen - 1) / 2];
+    }
+    return medianNr;
+  }
+
+  static getFeesInRange(transactions: TransactionExtended[], rangeLength: number) {
+    const arr = [transactions[transactions.length - 1].feePerVsize];
+    const chunk = 1 / (rangeLength - 1);
+    let itemsToAdd = rangeLength - 2;
+
+    while (itemsToAdd > 0) {
+      arr.push(transactions[Math.floor(transactions.length * chunk * itemsToAdd)].feePerVsize);
+      itemsToAdd--;
+    }
+
+    arr.push(transactions[1].feePerVsize);
+    return arr;
+  }
+}
diff --git a/backend/src/api/mempool-blocks.ts b/backend/src/api/mempool-blocks.ts
index a142d50da..a39330d5e 100644
--- a/backend/src/api/mempool-blocks.ts
+++ b/backend/src/api/mempool-blocks.ts
@@ -1,5 +1,6 @@
 const config = require('../../mempool-config.json');
 import { MempoolBlock, TransactionExtended } from '../interfaces';
+import { Common } from './common';
 
 class MempoolBlocks {
   private mempoolBlocks: MempoolBlock[] = [];
@@ -46,7 +47,8 @@ class MempoolBlocks {
     return mempoolBlocks;
   }
 
-  private dataToMempoolBlocks(transactions: TransactionExtended[], blockSize: number, blockVSize: number, blocksIndex: number): MempoolBlock {
+  private dataToMempoolBlocks(transactions: TransactionExtended[],
+    blockSize: number, blockVSize: number, blocksIndex: number): MempoolBlock {
     let rangeLength = 4;
     if (blocksIndex === 0) {
       rangeLength = 8;
@@ -61,35 +63,10 @@ class MempoolBlocks {
       blockVSize: blockVSize,
       nTx: transactions.length,
       totalFees: transactions.reduce((acc, cur) => acc + cur.fee, 0),
-      medianFee: this.median(transactions.map((tx) => tx.feePerVsize)),
-      feeRange: this.getFeesInRange(transactions, rangeLength),
+      medianFee: Common.median(transactions.map((tx) => tx.feePerVsize)),
+      feeRange: Common.getFeesInRange(transactions, rangeLength),
     };
   }
-
-  private median(numbers: number[]) {
-    let medianNr = 0;
-    const numsLen = numbers.length;
-    if (numsLen % 2 === 0) {
-        medianNr = (numbers[numsLen / 2 - 1] + numbers[numsLen / 2]) / 2;
-    } else {
-        medianNr = numbers[(numsLen - 1) / 2];
-    }
-    return medianNr;
-  }
-
-  private getFeesInRange(transactions: TransactionExtended[], rangeLength: number) {
-    const arr = [transactions[transactions.length - 1].feePerVsize];
-    const chunk = 1 / (rangeLength - 1);
-    let itemsToAdd = rangeLength - 2;
-
-    while (itemsToAdd > 0) {
-      arr.push(transactions[Math.floor(transactions.length * chunk * itemsToAdd)].feePerVsize);
-      itemsToAdd--;
-    }
-
-    arr.push(transactions[0].feePerVsize);
-    return arr;
-  }
 }
 
 export default new MempoolBlocks();