Enter your start date, adjust the phase lengths — and you get the day you cut, plus the day the harvest is actually jarred. Free, no sign-up.
The flowering time is on the seed packet — it is the most reliable figure here. The vegetative time is yours to choose; it decides how big the plant gets. With autoflowers there is no free veg period: the breeder gives you a total time from germination.
| Type of grow | Vegetative | Flowering | Total |
|---|---|---|---|
| Autoflower | 3 weeks | 7 weeks | 89 days 12.7 weeks |
| Photoperiod (hybrid) | 6 weeks | 9 weeks | 127 days 18.1 weeks |
| Sativa-leaning, long flower | 8 weeks | 11 weeks | 157 days 22.4 weeks |
Each figure includes 12 to 14 days of drying. They are reference points — the flowering time of your strain is on the packet and beats any table.
These calculators give you reference values for your own judgement. They replace neither a measurement on site nor expert advice — all figures without guarantee.
The sum is plain date arithmetic: start date + germination + veg + flower. That gives you the day you cut. Add the drying time and you get the day the harvest is actually finished — and that is another ten to fourteen days.
The most reliable figure in that chain is the flowering time: it is on the seed packet, and breeders are usually honest about it. The vegetative time is the one you choose — it decides how big the plant gets and is the only lever you have over the total length.
Germination and the seedling phase take one to two weeks and vary little. Which leaves the veg period as the part you actually plan with.
Almost every timeline you find online ends at the cut. That is where the grow ends for the plant — but not for you. Between the harvest and the first jar there are another ten to fourteen days, and they are not optional.
Freshly cut flower is three quarters water. Jar it too early and it moulds; dry it too fast and you lose the terpenes that made the strain worth growing. Neither can be repaired afterwards, which is why the drying time is a fixed part of this calculator rather than a footnote.
And it matters for planning: if you need the tent free for the next cycle, the flower is still hanging in it for two more weeks. That is the difference between a schedule that works and one that collides with itself.
What is left after drying — the number that actually counts — is what the yield calculator works out.
Autoflowers do not work the way the calculator above assumes by default, and it is worth knowing why. They flower on a timer, not on a light schedule — so there is no vegetative period you can extend or shorten.
What the breeder gives you is a total time from germination, usually nine to eleven weeks. To plan one, split that time across the fields: roughly three weeks as vegetative and the rest as flowering. The total comes out right, even though the boundary between the two is blurred in reality.
The trade-off: what you lose in control, you gain in predictability. An autoflower schedule holds far better than a photoperiod one, because the plant is not waiting for you to flip the lights.
A plan is a starting point, not a promise. Three things move the date in practice, and all three move it later.
The flowering time on the packet is a lower bound. It was measured under good conditions. One to two weeks longer is normal, especially with temperature swings, too little light, or stress from repotting and heavy defoliation. Plan with the upper end of the stated range.
Stress costs time. Topping, transplanting or a pest problem in veg sets the plant back a few days each time — not dramatic on its own, but it adds up. Training early rather than late keeps that cost down.
The trichomes decide, not the calendar. The calculated date tells you when to start looking, not when to cut. Milky trichomes with a few amber ones is the signal; a date in a calculator is not. If in doubt, the plant is right and the plan is wrong.
The first cycle is a plan. The second is a comparison. From the third on, you know your own numbers — how long your strains actually take in your tent, and how far the packet figure was off.
That only works if the real dates get recorded as they happen: when germination started, when you flipped, when you cut. Three cycles of that beat any table of typical values — including the one above.
Add germination, veg and flowering time to your start date. The flowering time is on the seed packet and is the most reliable of the three; the veg period is the one you choose. Add another ten to fourteen days of drying for the day the harvest is actually ready.
For a photoperiod strain indoors, roughly three to five months from seed to a jarred, cured harvest. Autoflowers are faster at around 70 to 100 days total. The table above gives three typical schedules, drying included.
Ten to fourteen days, hung at around 18 °C and 60 percent humidity. Faster is possible but costs quality: the flower dries on the outside while staying wet inside, and the terpenes go with the speed. Curing in jars comes after that and takes another two to four weeks.
Take the breeder's total time from germination — usually nine to eleven weeks — and split it across the fields: about three weeks as vegetative, the rest as flowering. Autoflowers flower on a timer, so there is no veg phase you can lengthen or shorten, which also makes their schedule more predictable than a photoperiod one.
By the trichomes, not by the calendar. Mostly milky with a few amber ones is the usual signal; clear means too early, mostly amber means past the peak. A jeweller's loupe or a phone macro lens is enough to see it. The calculated date tells you when to start checking.
Because the stated figure was measured under good conditions. One to two weeks longer is entirely normal, particularly with temperature swings, insufficient light, or stress from repotting and heavy defoliation. Plan with the upper end of the range the breeder gives.
Yes, but remember the drying: the flower hangs in the tent for another two weeks after the cut. If the next cycle needs the same space, the schedules collide. Either dry elsewhere or start the next germination during the drying period.
Yes. This calculator uses the same phases and the same arithmetic as the grow planner in the CRIS app. In the app the dates are attached to the actual grow, so the plan and what really happened stand side by side.
CRIS keeps the planned dates next to the real ones — germination, flip, cut, jarred. After three cycles you plan with your own numbers instead of a table. Offline, no account.