This missed pill calculator has been built by The Lowdown medical team using (FSRH) Faculty of Sexual and Reproductive Healthcare guidelines. The FSRH is the leader in the field of sexual and reproductive healthcare, and the voice for healthcare professionals working in this area.
They set clinical guidance and standards, provide training and lifelong education, and champion safe and effective sexual and reproductive healthcare across the life course for all. FSRH guidelines are developed using the best available evidence
This calculator can be used as part of a holistic consultation process to support effective decision making, and as part of considering the risk of unplanned pregnancy, but is not intended to replace medical advice. The calculator can support you in the choice you make for effective contraception methods for you, including whether long-acting reversible contraception (LARC) is more appropriate for you.
Decisions regarding your contraception choices should always include discussion with a healthcare professional. Further information about the FSRH can be found here.
Our calculator has also been endorsed by the Primary Care Women’s Health Forum.
All birth control pills have ‘safe windows’ for pill taking, which means that if you take your pill within a certain time frame, you are still protected against pregnancy.
Different types of pills have different safe windows, but everyone is advised to take their pill around the same time each day to maximise your level of protection through routine. Always check what kind of pill you are on.
If you change your usual pill taking time, but still take your pill within the safe window, this is classed as a ‘late pill’ and you’re still protected against pregnancy.
However, a ‘missed pill’ means that you have not taken your pill at your usual time and then exceeded the safe window for your particular pill. This means that you may not be protected against pregnancy.
Missing a pill can make it less effective, as well as vomiting, some medications, poor absorption from digestive issues (not including irritable bowel syndrome) and not starting a new pack on time.
These can all put you at risk of pregnancy, and may mean you need to use emergency contraception or additional birth control such as condoms.
If you think you may need to use it, check out our guide to emergency contraception and the morning after pill.
Always take your missed pill as soon as possible, sometimes this will mean you take two in one day.
The advice on missed pills is different depending on whether you are using the progestogen-only pill or the combined pill, and also which brand of pill you are using.
Our calculator can be used for the most common types of progestogen-only or mini pill, and most of the common combined pill brands.
The advice around missed pills for some brands such as Daylette, Eloine or Zoely (which contain placebo sugar pills) or Qlaira and Logynon which are multiphasic (with varying levels of hormones in individual pills) is more complex. If you are using these pills please consult the pill packet instructions or your healthcare provider for advice.