Income & Employment Guides UK — Maximise Your Earnings

Overtime Calculator UK — How to Calculate Overtime Pay

How to calculate overtime pay at time and a half, double time, or standard rates. Includes overtime calculation formulas, tax implications, Working Time Regulations, and ready-to-use tables.

By PocketWise · · 6 min read

Salary and income data is based on ONS and other official UK statistical sources. Figures are averages and may not reflect your individual circumstances.

Understanding how to calculate overtime pay helps you check your payslips and negotiate fair compensation for extra hours worked.

Overtime Rate Types

Common Overtime Rates

Rate Type Multiplier Formula Example (£15/hr base)
Standard (1×) 1.0 Base rate £15.00
Time and a quarter 1.25 Base × 1.25 £18.75
Time and a third 1.33 Base × 1.33 £19.95
Time and a half 1.5 Base × 1.5 £22.50
Double time 2.0 Base × 2.0 £30.00

When Each Rate Typically Applies

Rate Common Situations
Standard (1×) Weekday overtime, first few OT hours
Time and a quarter Some shift work
Time and a half Evenings, Saturdays, overtime beyond set hours
Double time Sundays, bank holidays, night shifts

Note: These are common arrangements, not legal requirements.

Basic Overtime Calculation

The Formula

Overtime Pay = Overtime Hours × Hourly Rate × Multiplier

Step-by-Step Example

Scenario: You earn £16/hour and worked 5 hours overtime at time and a half.

Step Calculation
1. Hourly rate £16.00
2. Multiplier (time and a half) 1.5
3. Overtime rate £16 × 1.5 = £24.00
4. Hours worked 5
5. Overtime pay £24 × 5 = £120.00

Overtime Pay Tables

Time and a Half Rates

Base Hourly OT Rate (1.5×) 5 Hours OT 10 Hours OT 20 Hours OT
£10.00 £15.00 £75 £150 £300
£12.00 £18.00 £90 £180 £360
£12.21 (NMW) £18.32 £92 £183 £366
£14.00 £21.00 £105 £210 £420
£15.00 £22.50 £113 £225 £450
£16.00 £24.00 £120 £240 £480
£18.00 £27.00 £135 £270 £540
£20.00 £30.00 £150 £300 £600
£22.00 £33.00 £165 £330 £660
£25.00 £37.50 £188 £375 £750
£30.00 £45.00 £225 £450 £900

Double Time Rates

Base Hourly OT Rate (2×) 5 Hours OT 10 Hours OT 20 Hours OT
£10.00 £20.00 £100 £200 £400
£12.00 £24.00 £120 £240 £480
£12.21 (NMW) £24.42 £122 £244 £488
£14.00 £28.00 £140 £280 £560
£15.00 £30.00 £150 £300 £600
£16.00 £32.00 £160 £320 £640
£18.00 £36.00 £180 £360 £720
£20.00 £40.00 £200 £400 £800
£22.00 £44.00 £220 £440 £880
£25.00 £50.00 £250 £500 £1,000
£30.00 £60.00 £300 £600 £1,200

Calculating Hourly Rate from Salary

If You’re Salaried

Your hourly rate: Annual Salary ÷ 52 ÷ Weekly Hours

Annual Salary Weekly Hours Hourly Rate
£25,000 37.5 £12.82
£30,000 37.5 £15.38
£35,000 37.5 £17.95
£40,000 40 £19.23
£45,000 40 £21.63
£50,000 40 £24.04

Salaried Overtime Example

Scenario: £35,000 salary, 37.5 hour week, 8 hours overtime at time and a half

Step Calculation
Hourly rate £35,000 ÷ 52 ÷ 37.5 = £17.95
Time and a half £17.95 × 1.5 = £26.93
Overtime earnings £26.93 × 8 = £215.44

Mixed Rate Overtime

When Different Rates Apply

Many employers use tiered overtime rates:

Hours Rate
First 40 hours Standard (1×)
41-48 hours Time and a half (1.5×)
Over 48 hours Double time (2×)

Mixed Rate Example

Scenario: £15/hour base, worked 52 hours in one week

Hours Rate Calculation Amount
40 hours 1× (£15) 40 × £15 £600.00
8 hours (41-48) 1.5× (£22.50) 8 × £22.50 £180.00
4 hours (49-52) 2× (£30) 4 × £30 £120.00
Total £900.00

Annual Overtime Earnings

Regular Weekly Overtime

Base Rate OT Rate (1.5×) OT Hours/Week Extra/Week Extra/Year
£12 £18 5 £90 £4,680
£12 £18 10 £180 £9,360
£15 £22.50 5 £113 £5,850
£15 £22.50 10 £225 £11,700
£18 £27 5 £135 £7,020
£18 £27 10 £270 £14,040
£20 £30 5 £150 £7,800
£20 £30 10 £300 £15,600

Impact on Annual Salary

Base Salary Regular OT (5 hrs/wk at 1.5×) Total Annual
£25,000 £4,993 £29,993
£30,000 £5,991 £35,991
£35,000 £6,990 £41,990
£40,000 £7,488 £47,488

Tax on Overtime

How Overtime Is Taxed

Overtime is taxed as normal income — same rates as your basic pay:

Total Annual Income Tax Rate
Up to £12,570 0%
£12,571-£50,270 20%
£50,271-£125,140 40%
Over £125,140 45%

Tax Trap Example

Scenario Base + OT Total Tax Impact
Before OT £48,000 - £48,000 All at 20%
With £5,000 OT £48,000 £5,000 £53,000 £2,730 taxed at 40%

The £5,000 OT pays: £5,000 - £1,092 (40% on £2,730) - £400 (20% on £2,000) - £92 (NI 2%) = ~£3,416 net

Overtime Net Pay Estimates

Gross OT Basic Rate (20%) Higher Rate (40%)
£100 ~£68 net ~£48 net
£200 ~£136 net ~£96 net
£500 ~£340 net ~£240 net
£1,000 ~£680 net ~£480 net

Including NI at 12%/2%

Working Time Regulations

Regulation Limit
Maximum working week 48 hours average (over 17 weeks)
Can opt out Yes — must be voluntary
Night workers 8 hours per 24-hour period
Rest breaks 20 mins if working 6+ hours
Daily rest 11 hours between shifts
Weekly rest 24 hours per week (or 48 per fortnight)

Opting Out of 48-Hour Week

Factor Detail
Must be voluntary Can’t be forced
In writing Written agreement required
Can cancel With 7 days to 3 months notice
Still need breaks Rest requirements still apply

Overtime and Minimum Wage

Your total pay ÷ total hours must meet NMW:

Scenario Base Hours OT Hours Total Hours Total Pay Per Hour NMW Check
OK 37.5 10 47.5 £570 £12.00 Below NMW!
OK 37.5 10 47.5 £580 £12.21 At NMW ✓
OK 37.5 10 47.5 £650 £13.68 Above NMW ✓

If unpaid overtime reduces your effective rate below NMW, that’s illegal.

Salaried Workers and Unpaid Overtime

Calculating Your True Hourly Rate

Salary Contracted Hours Actual Hours Worked True Hourly Rate
£35,000 37.5 37.5 £17.95
£35,000 37.5 45 £14.96
£35,000 37.5 50 £13.46
£35,000 37.5 55 £12.24

Is It Worth the Overtime?

Questions to consider:

Factor Consider
Paid overtime? If not, what’s true hourly rate?
Career benefit? Does it help promotion prospects?
Expectation? Is it genuinely expected?
Sustainable? Can you maintain it long-term?
Alternatives? Could that time earn money elsewhere?

Bank Holiday and Weekend Rates

Common Premium Rates

Day/Time Typical Rate £15/hr Example
Saturday 1.25-1.5× £18.75-£22.50
Sunday 1.5-2× £22.50-£30.00
Bank holiday 1.5-2× £22.50-£30.00
Night shift 1.25-1.5× £18.75-£22.50

Bank Holiday Earnings Example

Working Christmas Day at £15/hour double time:

Hours Calculation Amount
8 hours 8 × £30 £240

vs normal day: 8 × £15 = £120

Extra earned: £120

TOIL (Time Off In Lieu)

How TOIL Works

Factor Detail
What it is Time off instead of overtime pay
Calculation Usually hour-for-hour
Enhanced TOIL Sometimes 1.5 or 2 hours off per OT hour
When to take Agreed with employer

TOIL vs Overtime Pay

10 Hours OT Overtime Pay (1.5×) TOIL Value
£15/hr worker £225 gross (~£153 net) 10-15 hours off
£20/hr worker £300 gross (~£204 net) 10-15 hours off

TOIL may be better if:

  • You value time off
  • You’re in higher tax bracket
  • You need flexibility

Overtime pay may be better if:

  • You need the money now
  • Tax impact is minimal
  • TOIL is hard to take

Contracted vs Voluntary Overtime

Contracted Overtime

Feature Detail
In your contract Can be required
Refusal May be breach of contract
Rates Usually specified
Predictable Know what to expect

Voluntary Overtime

Feature Detail
Your choice Can decline
Availability May not always be offered
Rates Check before accepting
Flexibility Work when you want

Checking Your Payslip

What to Verify

Item Check
Hours recorded Match your records?
Base rate Correct?
OT hours All recorded?
OT rate Correct multiplier?
Total gross Calculation correct?
Tax code Appropriate?
Deductions Expected amounts?

Dispute Process

Step Action
1 Raise with line manager
2 Contact HR/payroll
3 Formal grievance
4 ACAS early conciliation
5 Employment tribunal (if needed)

Summary

Type Calculation
Standard OT Hours × Base Rate
Time and a half Hours × (Base Rate × 1.5)
Double time Hours × (Base Rate × 2)
Mixed rates Calculate each tier separately, sum
After tax Gross OT × (1 - tax% - NI%)

Sources

  1. GOV.UK — Maximum weekly working hours