Sitters run short for one predictable reason: the food was estimated by eye from a bag, and a bag's contents bear no reliable relation to the number of days it covers. The fix is arithmetic done once, at leisure, before the trip. Measure what your animals genuinely eat on ordinary days, multiply by the days you will be away, add a clear buffer, and then portion or label the result so the sitter never has to guess, improvise, or ration. This is a measuring exercise, not a shopping exercise, and it starts a week before you leave rather than the night before.
Measure a Real Day First
For three or four ordinary days, measure everything as you feed it and write the amounts down. Weigh or scoop the pellets exactly as you serve them, and count hay in a unit you can repeat, such as large handfuls, noting how much of yesterday's hay is actually gone by morning rather than merely scattered. Small mammals waste hay cheerfully, pulling it into bedding and sitting on it, so measure what disappears, top-ups included, and not what the packet suggests an animal of that size ought to eat. Your own animals' real days are the only figures worth multiplying.
Take the daily figures animal by animal where animals are fed separately, and as a household total where they share. A growing youngster, an elderly animal on a different pellet, or a hay-only patient each needs a separate line in the math, because a single blended average is how one animal's food quietly runs out while another's piles up.
Multiply, Then Add the Buffer
Now the worked example, with exact figures. Say your two guinea pigs eat one quarter cup of pellets a day between them. For a seven-day trip, one quarter cup times seven days is one and three-quarter cups. Add a two-day buffer, which is one quarter cup times two, a half cup, and the amount to leave is two and a quarter cups, covering nine days of pellets in total. Hay follows the same pattern: at four large handfuls a day between them, seven days needs twenty-eight handfuls, the two-day buffer adds eight handfuls, and you leave thirty-six handfuls, portioned or clearly marked, covering nine days.
The buffer is not generosity; it is engineering. It absorbs the spilled scoop, the delayed return, the day the sitter drops a portion on the floor, and the animal that eats more in your absence than in your presence. Keep the buffer food in its own labeled bag or section, marked as the reserve, so the sitter uses it only after the main portions and you can see at a glance on your return whether it was touched. Portion daily pellets into labeled day bags where you can, and bundle hay by the day, because a sitter counting out pre-portioned days cannot drift ahead of the math the way a sitter scooping from a shared sack can.
Agree It All in Writing
Get the amounts, the dates, and the feeding terms agreed with your sitter in writing before the trip: the daily pellet amount per animal, the daily hay amount, which bag is the reserve, what to do if food runs low despite the buffer, and what you are providing in return for the care. Written amounts end the two classic holiday failures, the sitter who overfeeds from kindness because no figure was given, and the sitter who underfeeds from caution for the same reason. Leave the written sheet where the food lives, next to the labeled portions, and walk the sitter through it once in person.
While you are away, a simple daily confirmation closes the loop between the math and the reality. Through Care Teams in KinsLe, the daily feeding round can be assigned to your sitter as a dated duty, and the completed round leaves its own time record, so a missed day is visible the same evening rather than at your return.