Brexit Cost Calculator

The Brexit Cost Calculator estimates a cumulative cost scenario from the 2016 UK referendum date through a date you choose. It is a neutral arithmetic model, not an official account and not an argument for or against Brexit. The form combines an editable weekly growth-loss assumption before 2020, an editable annual growth-loss assumption after 2020, and an optional fixed bundle of one-off public costs. It then converts the resulting total into two simple scale comparisons: equivalent hospitals and equivalent nurse-years.

Brexit cost estimates vary because analysts choose different baselines, counterfactuals, time periods, prices, and public-cost categories. This calculator makes its assumptions visible. If you disagree with the default weekly or annual loss, change it. If you want to exclude one-off public costs, switch them off. If you want a shorter or longer measurement period, change the through date. The result should always be described as a scenario generated by the form inputs.

How to use this calculator

Choose the calculate through date first. The date cannot be before 23 June 2016 in the input rules. Enter the pre-2020 weekly growth loss in pounds. The default is £440,000,000 per week. Enter the post-2020 annual growth loss in pounds. The default is £70,000,000,000 per year. Leave include one-off public costs on if you want the model to add its fixed bundle. Turn it off if you want to view only the two growth-loss components.

The result displays estimated cost through the selected date, pre-2020 growth loss, post-2020 growth loss, one-off public costs, equivalent hospitals, and equivalent nurse-years. To place a large national number beside everyday planning math, use the budget calculator, compound interest calculator, and savings goal calculator. Those links do not make the Brexit estimate personal; they simply provide familiar ways to think about cash-flow, compounding, and goal amounts.

What the calculator estimates

The model starts counting on 23 June 2016. It counts days through 1 January 2020 for the pre-2020 portion, unless the selected through date is earlier. It converts those days into weeks by dividing by 7 and multiplies by the weekly loss input. For dates after 1 January 2020, it counts days from 1 January 2020 through the selected date, divides by 365, and multiplies by the annual loss input. The calculation uses rounded day differences based on UTC dates.

If one-off costs are enabled, the model adds a fixed bundle. The constants are £39,000,000,000, £6,300,000,000, £129,100,000, £281,700,000, £156,000,000, and £4,600,000. Their sum is £45,871,400,000. The calculator labels that sum as one-off public costs. It then divides the total by £90,000,000 to produce equivalent hospitals and by £22,128 to produce equivalent nurse-years. These conversion figures are only scale devices in the form; they are not costed public spending plans.

Formula

The growth-loss portion is:

$\text{pre cost} = \frac{\text{pre-2020 days}}{7} \times \text{weekly loss}$

$\text{post cost} = \frac{\text{post-2020 days}}{365} \times \text{annual loss}$

The total is:

$\text{total} = \text{pre cost} + \text{post cost} + \text{one-off costs if included}$

The scale comparisons are:

$\text{equivalent hospitals} = \frac{\text{total}}{90000000}$

$\text{equivalent nurse-years} = \frac{\text{total}}{22128}$

Example

Use the default through date of 2026-06-21, a pre-2020 weekly loss of £440,000,000, a post-2020 annual loss of £70,000,000,000, and one-off public costs included. The date calculation counts 1,287 pre-2020 days from 23 June 2016 to 1 January 2020. Dividing by 7 gives about 183.86 weeks. Multiplying by £440,000,000 gives about £80,897,142,857 in pre-2020 growth loss.

The post-2020 period counts 2,363 days from 1 January 2020 to 21 June 2026. Dividing by 365 gives about 6.47 years. Multiplying by £70,000,000,000 gives about £453,178,082,192 in post-2020 growth loss. The one-off bundle is £45,871,400,000. Adding the three parts gives about £579,946,625,049, which the form rounds to a whole-pound currency display. The equivalent hospital comparison is about 6,444, and the equivalent nurse-year comparison is about 26,208,723.

If the one-off switch is turned off with the same date and growth assumptions, the total falls by exactly £45,871,400,000. The growth-loss components do not change. If the through date is extended, the post-2020 component grows by roughly the daily equivalent of the annual loss input. With the default £70,000,000,000 annual loss, each additional day after 2020 adds about £191,780,822 before rounding.

Neutral context and limits

The calculation is intentionally transparent but limited. It does not estimate GDP directly, identify a counterfactual trade path, discount future cash flows, adjust for inflation, separate public and private costs, or model benefits. It also does not update the default assumptions from live economic data. Users should treat the defaults as editable placeholders and cite their own source if they change the weekly or annual loss.

Large historical events can affect trade, migration, investment, regulation, public budgets, and exchange rates in ways that are difficult to isolate. A calculator with two loss rates and a fixed one-off bundle cannot capture that full evidence base. Its value is that every input is visible and the arithmetic is reproducible. Keep the language factual: “under these assumptions, the calculator estimates…” rather than “Brexit cost…” as a precise standalone claim.

For public communication, include the through date, the weekly and annual loss assumptions, whether one-off costs were included, and the date when the estimate was produced. Rules, data, and official publications change over time.

Sources

• GOV.UK, The transition period has ended — official UK government context for the post-transition period.
• GOV.UK, EU Withdrawal Agreement Bill — official context for withdrawal legislation.
• GOV.UK, The future relationship between the United Kingdom and the European Union — official context for UK-EU relationship documents.