diff --git a/src/main/java/Model/SaleCalculator.java b/src/main/java/Model/SaleCalculator.java
index 27fd394..93b6f93 100644
--- a/src/main/java/Model/SaleCalculator.java
+++ b/src/main/java/Model/SaleCalculator.java
@@ -1,36 +1,51 @@
 package Model;
+
 import java.math.BigDecimal;
 
+/**
+ * SaleCalculator class that calculates gross, commission, tax and total.
+ */
 public class SaleCalculator implements TransactionCalculator{
-    private BigDecimal purchasePrice;
-    private BigDecimal salesPrice;
-    private BigDecimal quantity;
-
-    public SaleCalculator(Share share) {
-        this.purchasePrice = share.getPurchasePrice();
-        this.salesPrice = share.getStock().getSalesPrice(); 
-        this.quantity = share.getQuantity();
-    }
-
-    public BigDecimal calculateGross() {
-        return this.salesPrice.multiply(this.quantity);
-    }
-
-    public BigDecimal calculateCommission() {
-        BigDecimal rate = new BigDecimal("0.01");
-        return calculateGross().multiply(rate);
-    }
-
-    public BigDecimal calculateTax() {
-        BigDecimal sellingCost = this.purchasePrice.multiply(this.quantity);
-        BigDecimal profit = calculateGross().subtract(calculateCommission()).subtract(sellingCost);
-        BigDecimal rate = new BigDecimal("0.3");
-        return profit.multiply(rate);
-    }
-
-    public BigDecimal calculateTotal() {
-        return calculateGross().subtract(calculateCommission()).subtract(calculateTax());
-    }
+  private BigDecimal purchasePrice;
+  private BigDecimal salesPrice;
+  private BigDecimal quantity;
+
+  /**
+   * Method with parameters.
+   *
+   * @param share share from calculator
+   */
+  public SaleCalculator(Share share) {
+    this.purchasePrice = share.getPurchasePrice();
+    this.salesPrice = share.getStock().getSalesPrice(); 
+    this.quantity = share.getQuantity();
+  }
+
+  @Override
+  public BigDecimal calculateGross() {
+    return this.salesPrice.multiply(this.quantity);
+  }
+
+  @Override
+  public BigDecimal calculateCommission() {
+    BigDecimal rate = new BigDecimal("0.01");
+    return calculateGross().multiply(rate);
+  }
+
+  /**
+   * Method that calculates tax.
+   */
+  public BigDecimal calculateTax() {
+    BigDecimal sellingCost = this.purchasePrice.multiply(this.quantity);
+    BigDecimal profit = calculateGross().subtract(calculateCommission()).subtract(sellingCost);
+    BigDecimal rate = new BigDecimal("0.3");
+    return profit.multiply(rate);
+  }
+
+  @Override
+  public BigDecimal calculateTotal() {
+    return calculateGross().subtract(calculateCommission()).subtract(calculateTax());
+  }