Know how often to water your plants. This free plant watering calculator suggests an interval from plant type, season and light, with the next date and a water amount by pot size.
Your plant
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Pick the plant type and adjust for season and light. The result is a guide interval — always check the top inch of soil and water when it’s dry rather than strictly by the clock.
Water every
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Choose your plant
Next watering
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Times per month
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Water per time
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Per month (approx)
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Watering frequency depends on plant, pot, soil, light, humidity and season — this gives a sensible starting interval. The biggest cause of houseplant death is overwatering, so let the topsoil dry between waterings and make sure pots drain.
Use this free plant watering calculator to find how often to water your plants. Choose the plant type and adjust for season and light to get a watering schedule and amount.
What this plant watering calculator does
A plant watering calculator suggests a watering interval from the plant type, then adjusts it for season and light. With a pot size, it also estimates how much water to give each time.
How the schedule is worked out
interval = base days × season factor × light factor
water per time ≈ 20% of the pot's soil volume
So a typical houseplant in spring with medium light lands around a 7-day interval, while a succulent in low winter light can stretch to 3–4 weeks.
Rough watering intervals
Plant
Typical interval
Herbs / vegetables
2–4 days
Tropical / thirsty
4–6 days
Typical houseplant
~7 days
Fern / shade plant
~10 days
Succulent / cactus
14+ days
Check the soil, not just the calendar
The schedule is a guide. Before watering, feel the top inch of soil — if it’s still damp, wait. Overwatering is the most common cause of houseplant death, so make sure pots drain freely.
How to use the plant watering calculator
Choose the plant type.
Adjust for season and light.
Add pot size for a water amount per watering.
Plant Watering FAQ
How often should I water my plants?
It depends on the plant — herbs every few days, typical houseplants about weekly, and succulents every two weeks or more. Adjust for season and light.
How much water does a plant need?
A rough guide is about 20% of the pot's soil volume each watering, until water drains from the bottom. Empty the saucer so roots don't sit in water.
Should I water on a fixed schedule?
Use the interval as a guide but check the soil — if the top inch is still damp, wait. Plants need less in winter and low light.
Why is overwatering a problem?
Soggy soil starves roots of oxygen and causes root rot. Overwatering kills more houseplants than underwatering, so let topsoil dry and ensure good drainage.
Do bigger pots need watering less often?
Often yes — more soil holds more moisture, so larger pots can go longer between waterings but need more water each time.
Is the plant watering calculator free?
Yes, this plant watering calculator is completely free, needs no sign-up, and gives instant results in your browser.
