I don't know how many fasts I owe. How do I work it out?
By estimating in good faith and making up that number. You are not required to produce an exact figure you cannot know: you work from a careful approximation and make it up. If you are torn between two figures, most scholars advise taking the higher one for peace of mind, though not all treat that as obligatory.
The honest answer turns on your circumstances. What it hinges on is below.
This is a very common situation — years of periods nobody wrote down, pregnancies, a stretch of not practising — and the law does not demand the impossible.
The principle that governs it: “Allah does not charge a soul except with that within its capacity. It will have the consequence of what good it has gained, and it will bear the consequence of what evil it has earned. "Our Lord, do not impose blame upon us if we have forgotten or erred. Our Lord, and lay not upon us a burden like that which You laid upon those before us. Our Lord, and burden us not with that which we have no ability to bear. And pardon us; and forgive us; and have mercy upon us. You are our protector, so give us victory over the disbelieving people."” (Qur’an 2:286)
And the instruction to make up, without prescribing a method of calculation: “Fasting for a limited number of days. So whoever among you is ill or on a journey during them - then an equal number of other days are to be made up. And upon those who are able to fast, but with hardship - a ransom as substitute of feeding a poor person each day. And whoever volunteers good i.e., excess - it is better for him. But to fast is best for you, if you only knew.” (Qur’an 2:184)
How it is done in practice:
1. Estimate by periods. This is more reliable than trying to recall individual days: for example, about seven days of menstruation per Ramadan, multiplied by the years. 2. Round up if unsure. Most advise this for peace of mind; not all make it obligatory. 3. Write it down and count off. The tracking is half the problem: with no record, the figure grows in your head and never comes down. 4. Make up at a sustainable rate. Mondays and Thursdays, or the short days of winter, is how most people clear it.
What your case depends on: how many years it is, what caused the loss — menstruation, illness, pregnancy, or not practising — your health now, and which school you follow, because for some causes there is fidya as well.
A note that takes the weight off: the anxiety about the figure does more damage than the figure. Many people never start making up because they do not know the exact number, and end up owing the same a year later. Estimate, begin, and ask about the details as you go.
- Qur’anQur’an 2:286
- Qur’anQur’an 2:184