Fiscal year calculator
A fiscal year (or financial year) is the 12-month period an organisation or government uses for accounting and tax — and it rarely lines up with the January calendar year. This tool tells you which fiscal year any date belongs to under the common conventions, and shows the exact start and end dates plus how much of the year is left.
How it works
You pick a date and a fiscal-year start month. The tool finds the most recent occurrence of that start on or before your date — that is the fiscal year your date falls in. It then sets the end date to the day before the next start, labels the year using each region’s naming style, and counts the total days in the period and the days remaining from your chosen date. Supported conventions:
| Convention | Starts | Ends |
|---|---|---|
| Calendar | 1 January | 31 December |
| UK government / corporate | 1 April | 31 March |
| UK personal tax (HMRC) | 6 April | 5 April |
| Australia | 1 July | 30 June |
| US federal | 1 October | 30 September |
Why fiscal years differ — and why it matters
Each convention exists for a specific historical or practical reason:
UK corporate (1 April). The UK government financial year begins 1 April, dating back centuries to the old calendar reform. UK companies often align their own financial year to this date for convenience with Corporation Tax filing, though they can choose any month-end.
UK personal tax (6 April). The personal tax year starts on 6 April, not 1 April. This six-day offset traces back to the 1752 calendar reform when Britain adopted the Gregorian calendar, losing 11 days, and adjusted the tax year accordingly. HMRC Self Assessment returns cover the tax year ending 5 April.
Australia (1 July). Australian income tax operates on the 1 July–30 June year. Companies report to ASIC on the same basis. The mid-year start aligns roughly with the Southern Hemisphere winter, when economic activity traditionally slows.
US federal (1 October). The US federal government fiscal year runs from 1 October to 30 September. It is labelled by the year in which it ends: FY2026 runs from 1 October 2025 to 30 September 2026. This naming convention catches people out when converting federal fiscal quarters to calendar dates.
Calendar year (1 January). Many private companies and most individuals worldwide use the standard calendar year for simplicity. Countries like Germany and the Netherlands typically require corporate accounts on a 31 December year-end unless there is a compelling reason to deviate.
Worked example
Take 15 February 2026 with the UK April convention. The most recent 1 April on or before that date is 1 April 2025, so the date falls in the fiscal year running 1 April 2025 – 31 March 2026. From 15 February there are 44 days remaining in that fiscal year.
The same date with the US federal convention falls in FY2026 (1 October 2025 – 30 September 2026), with 227 days remaining.
Naming style differences
Fiscal year labels differ by region. The UK corporate year beginning 1 April 2025 is typically called 2025/26. The US federal year beginning 1 October 2025 is FY2026. Australia’s year beginning 1 July 2025 is FY2025–26 or simply FY26. This tool formats the label to match the expected local convention so you get the right label for your jurisdiction.
All logic runs locally in your browser — nothing leaves your device. Always confirm your own jurisdiction’s rules and reporting deadlines before filing.