How long will it last
Days left, the run-out date, and a restock date from what you have and what you use per day.
When you want a supply duration for rice, toilet paper, pet food, or diapers.
How long will it last is remaining divided by one day’s use. It does not assume a standard amount.
What this tool does
It finds how many days the amount you have will last. An item preset only changes the starting unit. It does not assume a standard daily amount. Amounts, the item, and the result are not sent for measurement.
How the days are calculated
Days left are remaining divided by daily use. Only grams and kilograms convert, and only millilitres and litres. Counts, sheets, rolls, and uses stay separate.
Run-out and restock dates
The run-out date is the device’s local today plus the day count with the fraction dropped. The restock date is that date minus the lead days. The lead starts at 3.
Amounts for 7 and 30 days
Seven days is daily use times 7. Thirty days is times 30. The shortfall for the target is daily use times target days, minus what you have. It is 0 when you already have enough.
Examples
5000 g at 150 g a day lasts 33.33 days. 12 rolls at 0.5 rolls a day lasts 24 days. Rice of 5 kg uses the same formula once you enter your own daily amount.
Questions by item
How long will 5 kg of rice last?
This how long will it last calculator does not assume a rate. Enter 5 kg and your own daily grams or kilograms.
How long will toilet paper last?
Enter the rolls you have and the rolls you use per day. 12 rolls at 0.5 a day lasts 24 days.
How many days of tissues?
Enter the sheets you have and the sheets you use per day. No standard sheet count is filled in.
How long will detergent last?
Enter millilitres or litres for both amounts. A count is not converted into millilitres.
How long will pet food last?
Enter grams or kilograms. A standard amount per animal is not assumed.
How long will diapers last?
Enter the sheets you have and the sheets used per day. A standard count by age is not filled in.
How is the restock date found?
Subtract the lead days from the run-out date. The lead starts at 3 days, and the target starts at 30 days.