Know When to Reorder Before You Run Out
Find out how many days a bottle lasts and the date to order the next one.
This tool was built by Serge (MSc) using established science and government sources. My academic background covers plant biology, environmental biology, and biogeochemistry. My tools are for educational purposes and give practical guidance, not professional advice.
A bottle duration calculator takes the servings in a bottle and the servings you take each day, then tells you when the bottle runs out.
Add a start date and a shipping buffer, and you also get an order-by date.
Where to find the servings
Look for servings per container on the label. If it is not listed because a serving is one capsule, count the capsules in the bottle.
Take care with products where a serving is two or three capsules. The bottle count and the serving count are not the same number.
Why the date can drift
Skipped days, travel, and a change in your routine all move the date. Treat the result as a plan, not a promise.
The shipping buffer is there for the same reason. A week is a common starting point, but use what your seller usually takes.
Keep a simple record
The NIH Office of Dietary Supplements offers a printable My Dietary Supplement and Medicine Record for the name, dose, and how often you take each product. It pairs well with a reorder date, and it is handy to bring to appointments.
Compare before you reorder
Running low is a good moment to check price. The Cost Per Dose Calculator shows what each serving really costs, and the Supplement Stack Builder helps you see the whole routine in one place.
If you are comparing a powder with capsules, the Powder to Capsule Converter shows how many capsules a dose would take.
A note on serving size
The manufacturer sets the serving size on a label. The NIH Office of Dietary Supplements points out that your health care provider may recommend a different amount, so this tool only works out timing and never suggests a dose.
This tool is for general education only and is not medical or professional advice. Always check product labels and speak with a qualified professional before making decisions about supplements.