The fairest approach is to distribute interest in proportion to each person’s savings-month: the sum, month by month, of what they had saved up. Whoever saves more, and from earlier on, receives a larger share. Event income is usually split equally, and pending loans are deducted from what each person is owed.
What the savings-month is
For each month of the cycle, you take what the person had saved up to that month, and add up all the months. A person who pays $100,000 a month for 12 months accumulates $100,000 in the first month, $200,000 in the second and so on up to $1,200,000; their savings-month is the sum of those twelve balances: $7,800,000.
Someone who joins in month 7 also pays $100,000 a month, but only adds up six balances: $100,000 + … + $600,000 = $2,100,000.
Example with three people
| Person | Monthly installment | Months | Savings-month | Interest received |
|---|---|---|---|---|
| Ana | $100,000 | 12 | $7,800,000 | $339,130.44 |
| Beto | $100,000 | 6 (from month 7) | $2,100,000 | $91,304.34 |
| Carla | $50,000 | 12 | $3,900,000 | $169,565.22 |
The group has $600,000 in interest to distribute. Ana receives the largest share because she saved more and for longer; Beto receives less because his savings were accumulated for only half of the cycle. The three shares add up to exactly $600,000.00.
What happens with leftover cents
When you divide, the result is almost never an exact number of cents. If each share is rounded, the total can end up a few cents above or below. The correct way is to calculate each share rounded down to the cent and hand out the leftover one cent at a time, starting with the person with the largest share. That way the distribution always adds up to what is really there.
Events and expenses
- The group’s general expenses are subtracted from the interest before distributing.
- What bingos and raffles bring in (income minus costs) is usually split equally among those who save, because it does not depend on how much each person contributed.
- A person’s pending loans are deducted from what they are owed at closing.
Other possible rules
- Equal shares: simple, but it does not reward whoever saves more or whoever joined first.
- Proportional to final savings: ignores how long each peso was saved.
- Proportional to savings-month: rewards both amount and time; it is the rule NatIA Ahorro uses.
How NatIA Ahorro helps
NatIA Ahorro calculates each saver’s savings-month, shows a preview of the distribution before closing and does the division in exact cents, with the leftover handed out as explained above. Each member sees their share in their account statement.
Last updated: October 9, 2026. Written by the BankIA (jsadsAI) team. Educational content: it does not constitute financial or legal advice.
Frequently asked questions
What is “ahorro-mes” (savings-month)?
It is the sum, month by month, of what a person had saved up to that month. It measures how much, and since when, they saved.
Does someone who joins late lose out?
They receive less interest than someone who saved for the whole cycle, because their savings were in the fund for less time. What they paid in as savings they get back in full.
Does every group have to distribute this way?
No. It is the most common rule and the one NatIA Ahorro applies, but what matters is that the group’s rule is written down before you start.
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