Shared Parental Leave and Pay calculator

Shared Parental Leave is a redistribution, not a bonus

The most common misunderstanding about Shared Parental Leave is that it adds weeks. It does not. It takes the birth parent's maternity leave, cuts it short, and turns whatever is left into leave that either parent can take — together, in blocks, or staggered around each other's work.

That framing changes the decision completely. The question is not "how much extra can we get?" but "who spends which of the 52 weeks we already have, and what does the household lose or gain by moving them?"

The 50 and the 37

Statutory Maternity Leave is 52 weeks and Statutory Maternity Pay is 39. GOV.UK caps the shareable amounts at 50 weeks of leave and 37 weeks of pay. The missing two weeks at each end are compulsory maternity leave immediately after the birth, which exists for the birth parent's physical recovery and cannot be given away. In a factory it is four weeks rather than two.

Everything else is negotiable. A birth parent who takes 20 weeks of maternity leave frees 32 weeks of Shared Parental Leave. One who takes 39 frees 13. One who returns at 12 weeks frees 40, which is more leave than most partners' employers have ever had to process at once.

The money question has a clean answer

Statutory Maternity Pay is not paid at a flat rate throughout. For the first 6 weeks it is 90% of average weekly earnings with no cap at all. For the remaining 33 weeks it drops to the flat rate, or 90% of earnings if that is lower. Statutory Shared Parental Pay is paid at that flat rate for every one of its weeks — there is no equivalent of the uncapped opening stretch.

So the rule is short. Curtailing maternity leave before week 6 costs the household real money, because those six weeks are worth more as SMP than they can ever be worth as ShPP. Curtailing after week 6 costs nothing in statutory terms, because from that point the two payments are the same amount.

That is the statutory picture. It is worth checking the contractual one separately, because many employers enhance maternity pay well above the statutory minimum and rather fewer enhance Shared Parental Pay to match. If one employer pays six months at full salary for maternity leave and the other pays the statutory minimum for Shared Parental Leave, the arithmetic that matters is your two contracts, not GOV.UK's floor.

Notice is where plans die

Shared Parental Leave has a reputation for being complicated, and the complication is almost entirely in the notice rules rather than in the concept.

You must give your employer 8 weeks' notice to curtail maternity leave. You must give 8 weeks' notice of each block of Shared Parental Leave. You can book up to 3 separate blocks as of right; anything beyond that is at the employer's discretion, and a request for more can be refused or reshaped. Both parents give notice to their own employers, and each has to declare the other's entitlement and consent.

Practically, that means starting the paperwork about ten weeks before you want the first block, not eight, and it means the curtailment notice and the first booking notice usually go in together. Take-up of Shared Parental Leave has stayed low since it was introduced in 2015, and the administrative front-loading is a large part of why.

Eligibility is a two-sided test

This is the part that most often stops a plan before the notice periods get a chance to. The parent taking the Shared Parental Leave needs 26 weeks of continuous employment with the same employer by the qualifying week, and must still be employed when the leave starts. The other parent needs to have worked for at least 26 of the 66 weeks before the due date and earned at least a set minimum across 13 of them.

The two tests are different on purpose. Self-employment does not disqualify you from being the "other parent" — a self-employed partner can satisfy the employment and earnings test that lets an employed parent take the leave. What self-employment does rule out is taking the leave yourself, because Shared Parental Leave is an employment right.

The ways people actually use it

Three patterns come up repeatedly. The first is a straight handover: the birth parent returns to work at six or nine months and the partner covers the rest, which usually means the household never pays for childcare in the first year. The second is overlap, where both parents are off together for a few weeks around the birth or at a difficult transition. The third is a stagger, where blocks are slotted around each other's busy seasons.

All three are legal, and the third is the one the block-booking rules were designed for — though the three-block limit means a heavily fragmented plan needs an employer who is willing to agree to it.

The deadline nobody circles

Everything must be taken within the first year after the birth. Unused weeks do not roll over, cannot be cashed in, and are not transferable to a later child. They simply expire on the first birthday.

If you are deliberately holding weeks back — for a nursery settling-in period, a partner's quieter quarter, or the point when night waking has stopped being survivable — count backwards from that date rather than forwards from today, and remember the eight weeks of notice that have to fit inside the gap.

What it interacts with

Statutory Paternity Leave sits alongside Shared Parental Leave rather than inside it, and can be taken first. Neonatal Care Leave, for babies born on or after 6 April 2025, is added on top of both. Keeping-in-touch days exist for Shared Parental Leave too, under the name SPLIT days, and there are more of them than the maternity equivalent. None of those is modelled here; the tool answers the week arithmetic, which is the question that has to be settled before any of the rest matters.