This calculator allows you to enter you monthly income for each month throughout the tax year. The calculator then provides monthly PAYE and NI deductions and an annual figure overview of deductions so you can review monthly amounts and annual averages for standard payroll deductions. It is important to understand that National Insurance is calculated on the period you are paid. So, in this calculator which uses monthly payment payroll process, National insurance is calculated each month, so the thresholds apply to earnings within that month only. National Insurance Contributions are not like PAYE, if you earn more one month, you will pay more, you will not receive a rebate or balance of the National Insurance overpayment the next month if you earn less.
This PAYE and NI Calculator is designed for those who are paid monthly with different amounts earned each month. This is not unusual in the contracting industry or for self-employed individuals whose income can flex depending on their workload. The majority of employees however will be paid even split amounts across a twelve month period. If you are an employee, on a monthly salary, you are most likely better off using the Monthly Wage Calculator as this includes more detailed features including salary sacrifice, company pension deductions and differing tax codes.