Why use this calculator
Constructive dismissal is the hardest common employment claim to win and one of the easiest to misjudge financially. People resign in the middle of an intolerable situation, often on the advice of nobody, and only afterwards start asking what the claim might be worth and whether resigning cost them more than it recovered.
The arithmetic matters because it is frequently unfavourable: resigning ends your pay immediately, and if the claim fails you recover nothing at all, having given up the salary you would otherwise still be drawing. This calculator sets out the realistic upper end of the award so you can weigh it against the certainty of continued employment, and it models the quarter reduction a tribunal can apply when someone resigns without first putting a grievance in writing, which is the single most common own goal in these claims.
How to use it
- Enter your gross weekly pay before tax and your complete years of continuous service at the date your resignation took effect, together with your age on that date.
- Enter the number of weeks of pay you are claiming as lost, covering both the period since you resigned and the period you expect to remain on lower pay.
- Add the value of benefits you lost over that same period, such as employer pension contributions, a company car, private medical cover or a forfeited bonus.
- Finally, record whether you submitted a formal written grievance before resigning, because that single answer can change the compensatory award by a quarter.
What each result means
- Total estimated award
- What a successful claim might recover in total. It assumes you prove both the fundamental breach and that you resigned because of it, which is the difficult part.
- Room before the compensatory limit
- How much further your claimed loss could grow before the compensatory award reaches its limit, the lower of 52 weeks' gross pay and the statutory cap. Loss above that limit is not recoverable, however strong the claim.
- Award above the tax-free allowance
- The part of the estimated award above the £30,000 tax-free allowance for payments on termination of employment. That part is taxed as employment income, so the cash you receive will be lower. Any arrears of pay or notice pay inside the award are taxed in full whatever the total.
- Basic award
- The statutory element, worked out exactly as redundancy pay is, from your age, service and capped weekly pay. It does not depend on proving financial loss.
- Lost earnings claimed
- Gross pay for the weeks you claim to have lost. A tribunal will test this against what you did to find comparable work.
- Lost benefits claimed
- The cash value of non-salary benefits lost over the claim period. Employer pension contributions are usually the largest component and are often forgotten.
- Loss of statutory rights
- A conventional award of a few hundred pounds recognising that you must build up two years of service again before regaining unfair dismissal protection.
- Compensatory award before adjustment
- Your total claimed loss after the statutory cap but before any percentage adjustment for procedure or conduct.
- Acas Code reduction
- The cut a tribunal may apply for unreasonably failing to follow the Acas Code, which for an employee usually means resigning without raising a grievance first.
- Compensatory award after adjustment
- The compensatory figure once the Acas adjustment is applied. This is the part of the award that is actually at risk from procedural failings.
The formula
Basic award = capped weekly pay x weeks earned from age and service, identical to statutory redundancy pay
Compensatory award = (gross weekly pay x weeks of loss) + benefits lost + £600 loss of statutory rights, limited to the lower of 52 weeks' gross pay or £123,543
Where no grievance was raised, the tribunal may reduce the compensatory award by up to 25 per cent for unreasonable failure to follow the Acas Code.
Total = basic award + adjusted compensatory award
How this number is used in practice
The legal test has three limbs and all three must be satisfied. There must be a fundamental breach of contract by the employer, you must resign in response to that breach rather than for some other reason, and you must not delay so long that you are treated as having accepted the new state of affairs.
Unilateral pay cuts, demotion without agreement, a sustained failure to deal with bullying or harassment, and conduct that destroys mutual trust and confidence all qualify. Being unhappy, passed over or badly managed does not. The delay limb catches a surprising number of claimants, and there is no fixed period after which it is too late, but weeks are safer than months.
Because resignation cuts off income immediately, the practical advice is almost always to raise a formal written grievance and give the employer a chance to respond before resigning. It preserves the claim, it produces a contemporaneous record of the breach, and it removes the twenty-five per cent reduction this calculator models.
Many employees who follow that route find the grievance either resolves the problem or produces a settlement agreement, which pays the first thirty thousand pounds tax free and avoids the evidential burden of proving constructive dismissal at a hearing.
Where the underlying conduct was discriminatory, such as harassment connected to a protected characteristic, the discrimination claim is usually worth more than the constructive dismissal claim standing beside it. Discrimination compensation has no statutory cap, includes an injury to feelings award under the Vento bands, and does not require two years of service. Claimants frequently plead only constructive dismissal and leave the more valuable claim on the table.
Worked examples
A 42-year-old earning £750 a week with 7 years' service, claiming 26 weeks' loss and £3,000 of benefits, grievance raised
Basic award of £5,625 from 7.5 weeks' entitlement, plus a compensatory award of £23,100, giving £28,725 in total
The same case where the employee resigned without submitting a grievance
The compensatory award is cut by 25 per cent, costing £5,775 and reducing the total from £28,725 to £22,950
A 55-year-old earning £2,000 a week with 20 years' service claiming a full year of loss
The basic award is £20,277 and the compensatory award is held to £104,000 by the 52-week rule, giving £124,277 in total
When people use it
- Weighing the value of a claim against the salary you give up by resigning
- Deciding whether to raise a grievance and stay, or resign and claim
- Employers assessing exposure when an employee has raised a grievance threatening resignation
- Advisers setting a settlement range during Acas early conciliation
- Quantifying a claim before signing a settlement agreement offered on exit
Tips
- Put a formal grievance in writing before resigning. It preserves the claim, creates evidence, and avoids a reduction of up to a quarter of the compensatory award.
- Do not delay. Continuing to work for months after the breach without protest suggests you accepted it, which defeats the claim entirely.
- Resign in writing and say plainly that you are resigning because of the breach, identifying it. A bland resignation letter is used against claimants constantly.
- Include employer pension contributions in the benefits figure. On a long claim period they are often worth more than any other single benefit.
- Check whether the conduct was discriminatory. If it was, that claim is uncapped, needs no qualifying service and adds an injury to feelings award.
- Start Acas early conciliation within three months less one day of your last day of employment, not of the breach itself.
What it assumes, and where it stops being accurate
- Uses the statutory limits in force from 6 April 2026. A resignation effective before that date falls under the previous year's limits.
- Assumes the claim succeeds. Constructive dismissal has a notably low success rate, so weight the result by your realistic chance of proving the breach.
- The Acas reduction is modelled at the full 25 per cent where no grievance was raised. A tribunal has discretion to apply anything from nothing up to that maximum.
- No Polkey reduction or contributory fault deduction is applied, and no account is taken of a failure to mitigate loss.
- Any parallel discrimination claim is excluded. Where one exists it is usually the larger claim and is not capped.
- Assumes continuous employment with one employer throughout the period of service entered.
Terms used on this page
- Fundamental breach
- A breach of contract serious enough to entitle the employee to treat the contract as at an end.
- Affirmation
- Continuing to work without protest after a breach, which is treated as accepting it and defeats the claim.
- Mutual trust and confidence
- An implied term in every employment contract; conduct destroying it is a fundamental breach.
- Acas Code
- The statutory code on discipline and grievance; unreasonable failure to follow it adjusts awards by up to 25 per cent.
- Settlement agreement
- A binding contract ending employment claims, usually paying the first £30,000 free of income tax.
Questions people ask
- What counts as a fundamental breach of contract?
- A breach serious enough to go to the root of the contract. Common examples are an imposed pay cut, an unagreed demotion, a sustained failure to address bullying or a safety complaint, and conduct that destroys mutual trust and confidence. Poor management or ordinary unfairness on its own is not enough.
- How likely am I to win a constructive dismissal claim?
- Success rates are low compared with ordinary unfair dismissal, because the claimant carries the burden on all three limbs: the breach, the resignation in response to it, and the absence of delay. Contemporaneous written evidence, particularly a grievance and the employer's reply, changes the odds more than anything else.
- Must I raise a grievance before resigning?
- It is not a legal precondition, but failing to do so is an unreasonable failure to follow the Acas Code and lets the tribunal cut your compensatory award by up to twenty-five per cent. It also removes the best contemporaneous evidence that the breach happened and that you objected to it.
- Can I claim if I have under two years' service?
- Not for constructive unfair dismissal, which requires two years of continuous service. You may still have a wrongful dismissal claim for breach of contract, and if the employer's conduct related to a protected characteristic, a discrimination claim, neither of which needs any qualifying period.
- Should I work my notice after resigning?
- Usually not, because resigning with notice and working it can undermine the argument that the breach was so fundamental you could not continue. Most constructive dismissal resignations are with immediate effect, and the unpaid notice becomes part of the loss claimed.
- Is the compensation taxed?
- The first £30,000 of genuine compensation for loss of employment is normally free of income tax. Amounts above that are taxed as employment income. Sums that are contractually due anyway, such as unpaid wages, holiday pay or contractual notice, are taxable in full.
Use this with
Constructive Dismissal Compensation Calculator answers one part of the question. These pick up where it stops: Unfair Dismissal Compensation Calculator, Statutory Redundancy Pay Calculator, Discrimination Compensation Calculator and Notice Period Pay Calculator.
Where these figures come from
Figures and rules on this page follow United Kingdom law.
- The Employment Rights (Increase of Limits) Order 2026. The statutory instrument setting the limits used here, in force 6 April 2026
- GOV.UK: Calculate your statutory redundancy pay. Official redundancy entitlement tool and the age-banded weeks table
- GOV.UK: Redundancy: your rights. Week's pay cap of £751 and the £22,530 maximum
- Acas: Dismissals. Fair procedure, the Acas Code of Practice and the 25% uplift
- Employment Rights Act 1996, Part X and XI. Statutory basis for unfair dismissal, redundancy pay and notice
- GOV.UK: Employment tribunals. Time limits, Acas early conciliation and the hearing process
Constructive Dismissal Compensation Calculator produces an estimate for general information. It is not financial, tax, medical, legal or engineering advice. read the full disclaimer. Spotted a wrong number? Report it and it gets fixed. The form picks up this calculator and the inputs you used.