private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e) { if (e.ColumnIndex == 3 || e.ColumnIndex == 4) { string duration = dataGridView1.CurrentRow.Cells[3].Value.ToString(); decimal rate = Convert.ToDecimal(dataGridView1.CurrentRow.Cells[4].Value); dataGridView1.CurrentRow.Cells["Total"].Value = manager.CalculateTotal(duration, rate); } }