Guaranteed Hours Calculator
Calculate exactly how many guaranteed hours your employer must legally offer you under the Employment Rights Act 2025.
Your 12-Week Reference Period
Enter the number of hours you worked each week over the last 12 weeks.
Consultation Note: The exact rules for ERA 2025 are still being finalized. We have used a 12-week reference period and an 8-hour minimum threshold based on government consultation proposals.
Your Guaranteed Hours Offer
20.0 hrs / week
Under ERA 2025, your employer must legally offer you a contract guaranteeing this baseline every single week.
Do I have to accept this?
No. The new law forces your employer to offer you these hours, but you have the legal right to reject the offer and remain on your fully flexible zero-hours contract if that suits your lifestyle better.
What Are Guaranteed Hours Under the Employment Rights Act 2025?
For years, zero-hours contracts have allowed employers to legally offer workers zero hours of work in a given week, creating massive financial insecurity. The Employment Rights Act 2025 puts an end to this. If you regularly work on a zero-hours or casual contract, your employer is now legally obligated to offer you a contract with guaranteed hours that reflects the actual hours you work.
How Is the Reference Period Calculated?
To calculate your guaranteed offer, your employer must look back over a set "reference period". The government is currently consulting on the exact length, but it is expected to be 12 weeks. Our calculator lets you input your exact hours for each of the last 12 weeks to find your true average. If you take holiday during this period, your holiday hours still count toward your average—you can calculate your accrued holiday pay using our Zero Hours Holiday Pay Calculator.
What Threshold Hours Will Trigger the Right?
If you only work one hour a month, your employer will not be forced to give you a contract. The government consultation is debating a minimum threshold (likely between 8 and 20 hours per week) that must be met to trigger the right. Our calculator uses a conservative 8-hour threshold based on consultation documents. Make sure you check your Minimum Wage to ensure you are being paid legally for every single hour you input.
When Do Guaranteed Hours Rights Start?
The consultation closes in August 2026. Because employers need time to update HR software, these specific guaranteed hours rights are expected to activate in early 2027.
What to Do If Your Employer Doesn't Offer Guaranteed Hours
Once the law is active in 2027, failure to offer you a guaranteed hours contract is a breach of your employment rights. You should first raise a formal grievance with your employer. If they refuse, you can contact Acas and ultimately take them to an Employment Tribunal for compensation. Remember, the ERA 2025 also gives you compensation if they cancel a shift—check this with our Shift Cancellation Pay Calculator.
Employment Rights Act