To calculate basic salary, you need to know deduct allowances and any other deductions from gross salary and use this formula: Basic Salary[A1] = Gross Salary[B1] - (HRA[C1] + DA[D1] + Other Allowances [E1]+ Deductions[F1]). Label and input values in their columns. Put formula ‘= B1 -(C1+D1+E1+F1)’ in Basic Salary column and get the final value.