Contractor Calculator

One configurable contractor planning tool

Contractor rate and revenue planner

Start with the rate or revenue figure already known, configure a realistic billable schedule and compare every gross equivalent in one place.

What figure is already known?

Select the basis for the amount being entered.

Enter the gross amount before tax and personal deductions.

Time expected to be invoiced on a billable day.

Days expected to be invoiced in a typical working week.

Exclude holidays, contract gaps, sickness and non-billable periods.

Add business costs and a contingency reserve

These fields separate estimated business resources from gross revenue. They do not estimate personal take-home pay.

Complete rate picture

Equivalent rates and revenue

Enter a known rate or annual target to calculate the complete set of equivalents.

Results use the billable pattern entered in the form.

Use the result professionally

A rate conversion is only as useful as its assumptions.

The planner keeps the commercial inputs separate from tax and personal deductions. This makes it suitable for comparing a proposed rate, planning invoice capacity or working backwards from a gross billing target without presenting a generic take-home estimate as personal advice.

Start with a real commercial figure

Use the amount in a proposal, contract or billing target before VAT. The planner treats it as gross revenue rather than salary or disposable income.

Use invoiceable time

Billable hours and days should represent time the client will pay for. Administration, proposals, training and gaps between engagements may reduce the available schedule.

Compare the downside as well as the target

The scenario table shows how four fewer billable weeks affect the result. A quote should remain commercially understandable when the working year is less than ideal.

Transparent methodology

How the five equivalents are calculated

Every starting figure is first expressed as gross annual revenue using the entered billable pattern. The other figures are then derived from that common annual value. This avoids mixing a 46-week revenue plan with a hidden 52-week assumption elsewhere on the page.

  • annual = hourly × hours/day × days/week × weeks/year
  • annual = day rate × days/week × weeks/year
  • annual = weekly revenue × weeks/year
  • annual = monthly revenue × 12
  • day rate = annual ÷ (days/week × weeks/year)

Currency calculations use decimal arithmetic and half-up rounding to two decimal places. The optional available-before-tax figure subtracts entered annual business costs and the selected percentage reserve from gross annual revenue. It does not estimate corporation tax, Income Tax, National Insurance, VAT or pension treatment.

Worked commercial examples

Three ways to use the same planning model

First contract: work back from an annual target

Starting point
£92,000 annual gross billing target
Billable pattern
8 hours a day, 5 days a week, 46 billable weeks

The required equivalents are £50.00 per hour, £400.00 per day, £2,000.00 per week and £7,666.67 per average month.

Reducing the expected year to 42 billable weeks does not change the annual target; it increases the rate required to reach it.

Established contractor: test a day rate

Starting point
£500 day rate
Billable pattern
5 billable days a week for 46 weeks

The schedule produces £115,000 gross annual revenue, equivalent to £62.50 per hour for an eight-hour billable day.

A conservative 42-week schedule produces £105,000, making the £10,000 exposure to unbilled time visible before personal deductions.

Fractional work: compare a monthly retainer

Starting point
£4,000 monthly retainer
Billable pattern
2 billable days a week, 7.5 hours a day, 46 weeks

The retainer represents £48,000 annual gross revenue, about £521.74 per billable day or £69.57 per billable hour under that delivery pattern.

The effective rate changes if the same retainer requires more delivery time, so the working assumptions should match the actual scope.

Editorial and technical review

Published by Contractor Calculator

Version 1 was reviewed on 24 August 2026. Every directional formula is validated against committed examples and boundary cases, including invalid values and division by zero. The page uses no market-rate or tax-threshold data.

For questions outside this arithmetic model, refer to the official GOV.UK guidance on self-employment and contracting, the Check Employment Status for Tax service and VAT registration guidance.

The broader calculation policy, correction process and testing approach are documented on the methodology page.

Common questions

Scope and interpretation

Does the planner estimate contractor take-home pay?

No. It calculates gross rate and revenue equivalents. Tax, National Insurance, VAT, pension contributions, company structure and personal deductions are outside its scope.

Why are billable weeks configurable?

A 52-week multiplier assumes every week can be invoiced. Editable billable weeks allow a plan to reflect leave, contract gaps, training, administration and business development without pretending one allowance fits every contractor.

How is monthly revenue calculated?

Monthly revenue is the calculated annual gross revenue divided by 12. A monthly retainer entered as the starting figure is multiplied by 12 before the other equivalents are calculated.

What does available before tax mean?

It is annual gross revenue minus the business costs and contingency reserve entered in the optional section. It is not disposable income or a tax estimate.

Can the result be used as a quote?

The result can inform a quote, but a commercial rate may also depend on scope, risk, demand, specialist experience, contract terms and payment terms. The planner does not decide the appropriate market price.