Sentencing Act 2026 calculator

Since 1 October 2026, most people in England and Wales serving an ordinary standard determinate sentence are released automatically at one-third of the sentence, instead of 40% (SDS40). Anyone sentenced on or after 1 October 2026 gets one-third from the start. People already in custody move by sentence length, from 1 October 2026 to 8 June 2027 (SI 2026/953 regulation 3). This calculator estimates the date. It is not the prison’s figure.

No. 1 October 2026 is when the rule started, not a single release day. People serving under 575 days moved that day. Longer sentences move on later dates, the next being 13 October 2026, then roughly monthly until 8 June 2027 (SI 2026/953 regulation 3). If someone has already passed the one-third point when their sentence length moves, they are released on that date.

This is an estimate. Added days for breaking prison rules, a recall, consecutive or mixed sentences, an excluded offence, or a different warrant date can all move the real date. Ask the offender manager or the prison. If you are worried, the Prisoners’ Families Helpline is free on 0808 808 2003.

No. Offences on the Sentencing Act 2026 exclusions list — including rape, serious child sex offences, unlawful killing, cruelty to a child, indecent assault, causing death by driving or cycling, and genocide — keep their old release point. Being excluded does not make the sentence longer. The change simply does not apply. Section 250 youth detention keeps its old point: 40% for most, 50% if the offence was left out of the 40% scheme, or two-thirds for seven years or more for a serious violent or sexual offence.

Probably. GOV.UK says release under the new rule comes with an electronic tag as the default, then a period of intensive supervision by probation. Licence conditions still apply, and breaking them can mean recall. Probation sets the exact conditions.

This is an estimate. The prison uses the warrant, added days, concurrent or consecutive mixes, and the official calculation. We count years at 365.25 days and months at 30.437 days, then apply the published fractions and the SI 2026/953 tranche dates. Only the prison or offender manager can confirm the date.

For most adults on a standard determinate sentence, HDC has not been routinely available since 2 September 2026. The earlier automatic release replaces it. That can mean a later date than a tag they were previously expecting. Youth HDC can still apply. This calculator does not add HDC.

SDS is a standard determinate sentence — a fixed length with automatic release, then licence. Most ordinary SDS now release at one-third, once the new rule has reached that sentence length. SDS+ is a shorter list under section 244ZA of the Criminal Justice Act 2003. For adults, those sentences move from two-thirds to one-half when the change reaches them, unless excluded.

Usually yes, in England and Wales. Days in custody for this offence come off the time left to serve. If they are still on remand, they do not have an automatic release date until the court sentences them. If remand already covers the custody part, they may leave when they are sentenced. Tagged bail (a qualifying curfew) can also count, at half a day each — this calculator only deducts days in custody. Only the prison or offender manager can confirm.