Ot Calculator
Free UK calculator — instant, accurate results for ot
⏱️ Overtime Calculator
📋 Embed This Calculator
Add the calculator widget (no navigation, no ads) to your website or blog. Copy the code below:
OT Calculator: Quick Overtime Earnings Tool
The OT calculator gives you an instant breakdown of overtime earnings based on your base hourly rate, number of OT hours, and the overtime multiplier. Whether your employer pays time-and-a-quarter, time-and-a-half, or double time, enter the figures and see exactly what you will earn before tax.
OT (overtime) in the UK is entirely governed by your contract. The Working Time Regulations 1998 limit average working hours to 48 per week (including overtime) unless you have opted out. There is no separate "overtime law" requiring premium rates — any enhanced rate is a contractual benefit, not a legal requirement.
Understanding OT Multipliers
| Multiplier | Name | Base £14/hr | OT Rate | 10 OT Hrs |
|---|---|---|---|---|
| 1.0× | Plain time/flat rate | £14.00 | £14.00 | £140 |
| 1.25× | Time and a quarter | £14.00 | £17.50 | £175 |
| 1.5× | Time and a half | £14.00 | £21.00 | £210 |
| 2.0× | Double time | £14.00 | £28.00 | £280 |
Weekday overtime is typically 1.0×-1.5×, Saturday overtime 1.5×, and Sunday/bank holiday overtime 2×. Check your contract or collective agreement for the applicable rates in your workplace.
OT and Your Financial Planning
Regular overtime can significantly boost income but be aware of the tax impact. If you consistently earn overtime, your tax code may be adjusted by HMRC to collect more tax monthly, avoiding a year-end underpayment. Track your OT earnings against the tax thresholds to avoid surprises.
For your base contracted salary calculation, use the pro rata calculator. To check whether regular overtime should be included in your holiday pay calculation, see our guide — post-Bear Scotland, regular overtime must be included in holiday pay for the first 4 weeks of entitlement.
How to Use the Ot Calculator
Using our ot calculator is straightforward. Follow these steps to get accurate results for your situation:
- Enter your full-time salary — This is the annual salary for the equivalent full-time role, before any deductions. You'll find this on the job advert or your contract.
- Set the full-time hours — The standard working week for the role. Most UK employers use 37.5 or 40 hours per week.
- Enter your actual hours — Your contracted weekly hours. This is the number you actually work.
- Click Calculate — The ot calculator displays your results instantly, with annual, monthly, weekly, daily, and hourly breakdowns.
Worked Example: Ot Calculator
Here's a real-world example using the ot calculator. James earns £14.50 per hour as a warehouse supervisor and works 10 hours of overtime per week at time-and-a-half.
Overtime rate: £14.50 × 1.5 = £21.75 per hour
Weekly overtime pay: £21.75 × 10 = £217.50
Monthly overtime: £217.50 × 52 ÷ 12 = £942.50
Annual overtime: £217.50 × 52 = £11,310
Combined with his standard 40-hour week (£14.50 × 40 = £580/week), James's total annual earnings are £30,160 + £11,310 = £41,470 before tax.
UK Overtime Rules You Should Know
- No legal right to overtime pay: UK law doesn't require employers to pay overtime — it depends on your contract. However, your average hourly pay must not fall below National Minimum Wage when overtime is included.
- Overtime and holiday pay: Since the Bear Scotland v Fulton ruling (2014), regular and systematic overtime must be included in holiday pay calculations. Use our overtime holiday pay calculator.
- Working Time Regulations: You cannot be forced to work more than 48 hours per week on average (over 17 weeks) unless you've opted out in writing.
- Tax on overtime: Overtime is taxed at your marginal rate — if it pushes you into the 40% bracket (above £50,270), you'll pay higher rate tax on the excess.
All calculations on this page follow ACAS pro rata pay guidelines and are consistent with the UK Employment Rights Act 1996. Tax figures use HMRC 2025/26 rates. The April 2025 National Living Wage of £12.21/hour is applied where relevant.
Related Salary Calculators
Our ot calculator is just one of the tools available on ProRataCalculator. You may also find these useful: pro rata calculator, term-time salary calculator, holiday pay guide.
Last updated: February 2026. Verified against HMRC 2025/26 tax rates and April 2025 National Living Wage (£12.21/hour).
Frequently Asked Questions
Overtime is typically calculated as hours worked beyond your contracted hours, multiplied by an enhanced rate. Common rates are time-and-a-half (1.5×) or double time (2×), though there is no legal requirement for enhanced overtime pay.
Yes, overtime pay is fully taxable. It is added to your regular earnings and taxed at your marginal income tax rate, with National Insurance contributions also applied.
There is no legal right to overtime pay in the UK. However, your total pay (including overtime hours) must not fall below the National Minimum Wage when averaged across all hours worked.
Regular, compulsory overtime should be included in holiday pay calculations. Voluntary overtime that follows a regular pattern may also need to be included, following the Bear Scotland case ruling.