Overtime Calculator Guide - Time and a Half UK

Overtime pay rates vary by employer and contract. This guide explains common overtime rates and how to calculate your additional earnings.

Common Overtime Rates

Calculating Overtime Pay

UK Overtime Rules

Working Time Regulations

• 48-hour week limit: Average max over 17 weeks (can opt out)
• Rest breaks: 20 minutes if working 6+ hours
• Daily rest: 11 consecutive hours between shifts
• Weekly rest: 24 hours off in each 7-day period

Calculating Your Hourly Rate

TOIL (Time Off In Lieu)

Some employers offer time off instead of overtime pay:

• 1 hour overtime = 1 hour TOIL (at basic rate)
• 1 hour overtime = 1.5 hours TOIL (at time and a half)
• Must be agreed in writing
• Should be taken within reasonable timeframe

Tax on Overtime

Overtime is taxed as normal income. If overtime pushes you into a higher tax bracket, only the amount above the threshold is taxed at the higher rate.

How Overtime Pay Calculations Work: The Methodology

Overtime pay calculations start with determining your base hourly rate. If you are paid a salary, your hourly rate is calculated by dividing your annual salary by the total number of working hours in a year. For a standard 37.5-hour week, this is 37.5 x 52 = 1,950 hours per year. For a 40-hour week, it is 2,080 hours per year. Your contractual hours may differ, so always check your employment contract for the exact figure.

Once you know your base hourly rate, the overtime rate is simply that figure multiplied by the relevant overtime multiplier. Time and a half (1.5x) is the most common overtime rate in the UK, particularly for weekday overtime and Saturday shifts. Double time (2.0x) is typically reserved for Sundays and bank holidays, though this varies by employer and industry.

For employees on zero-hours contracts or variable schedules, calculating overtime can be more complex. The National Minimum Wage (NMW) regulations require that your average hourly pay, when including all hours worked (including overtime), must not fall below the legal minimum. For workers aged 21 and over, the National Living Wage is £11.44 per hour (April 2024 rate, with increases expected in April 2025). If your employer pays a flat rate for overtime that would bring your average hourly earnings below this threshold, they are in breach of the law.

When calculating gross overtime earnings, remember to account for the cascading effect on tax and National Insurance. Overtime income is taxed as regular earnings. If your overtime pushes your total income from the basic rate band into the higher rate band (currently above £50,270 for 2025/26), only the portion above the threshold is taxed at 40%, not all of your overtime. Your employer's payroll system handles this automatically through the PAYE cumulative tax code system.

UK-Specific Context: Overtime Laws and Regulations

Unlike many other countries, the UK has no statutory right to enhanced overtime pay. The European Working Time Directive, as implemented in UK law through the Working Time Regulations 1998 (retained after Brexit), sets maximum working hours but does not mandate overtime pay rates. Your overtime pay is determined entirely by your employment contract, collective bargaining agreement, or company policy.

The Working Time Regulations limit the average working week to 48 hours, calculated over a 17-week reference period. Workers can voluntarily opt out of this limit by signing a written agreement, which is common in many UK industries. However, certain workers -- including those under 18, airline crew, and seafarers -- have specific protections that cannot be waived.

In the public sector, overtime arrangements are typically governed by nationally agreed pay frameworks. NHS staff on Agenda for Change contracts receive time and a third for weekday overtime, time and a half for Saturdays, and double time for Sundays and bank holidays. Police officers receive time and a third for overtime. Civil servants and local government workers have their own negotiated frameworks that vary by grade and department.

The private sector is far more varied. A 2024 survey by the CIPD (Chartered Institute of Personnel and Development) found that approximately 60% of UK employers offer some form of enhanced overtime pay, while 25% offer only flat-rate overtime (same hourly rate), and 15% expect unpaid overtime as part of salaried roles. The construction, manufacturing, and logistics sectors are most likely to offer enhanced overtime rates, while professional services and office-based roles more commonly include unpaid overtime expectations.

The question of whether overtime should be included in holiday pay calculations has been a significant legal issue in the UK. Following several Employment Tribunal and Supreme Court decisions (including the landmark Bear Scotland v Fulton case), regularly worked overtime -- whether compulsory or voluntary if it follows a regular pattern -- must be included when calculating holiday pay. This means your holiday pay should reflect your average earnings including overtime, not just your basic rate.

Worked Examples: UK Overtime Calculations

Common Mistakes and Tips

Frequently Asked Questions

Can my employer force me to work overtime?

This depends on your contract. If your contract includes a clause requiring you to work "reasonable" overtime, your employer can insist. However, they cannot compel you to work beyond the 48-hour weekly average (over 17 weeks) unless you have signed an opt-out. If overtime is not mentioned in your contract, you generally have the right to refuse. In practice, consistently refusing overtime when colleagues accept it may affect your working relationships and career progression.

Do I get paid overtime on a bank holiday?

There is no automatic legal right to enhanced pay on bank holidays in the UK. Your entitlement depends entirely on your contract. Many employers offer double time or time and a half for bank holiday work, but it is not a legal requirement. Statutory holiday entitlement in the UK is 5.6 weeks (28 days for a full-time worker), which can include bank holidays. If you work on a bank holiday, your employer must either pay you for it or give you a day off in lieu.

How does overtime affect my pension contributions?

For workplace auto-enrolment pensions, contributions are typically calculated on qualifying earnings between £6,240 and £50,270 (2025/26 thresholds). If your overtime pushes your total earnings higher within this band, both you and your employer will contribute more to your pension. Some employers calculate pension contributions on basic salary only, excluding overtime. Check your pension scheme rules to understand which earnings are pensionable.

Is TOIL better than overtime pay?

It depends on your financial situation and work-life balance preferences. From a purely financial perspective, overtime pay at enhanced rates is usually more valuable than equivalent TOIL hours. However, TOIL offers flexibility and rest, which has its own value. If offered TOIL at an enhanced ratio (e.g., 1.5 hours off for every 1 hour worked), it can be a good deal. Ensure any TOIL agreement is documented in writing, including the deadline by which time off must be taken.

James Mitchell, ACCA

Chartered Accountant & Former HMRC Advisor

James is a Chartered Certified Accountant (ACCA) specialising in UK personal taxation and financial planning. With over 12 years in practice and a background as a former HMRC compliance officer, he brings authoritative insight to complex tax topics.