Hatch: day 3 (all castes). Capped: queen day 8, worker 9, drone 10. Emerge: queen 16, worker 21, drone 24. Capped for: 8, 12 and 14 days. Upright egg: under a day old (Traynor 2018).
Honey bee life cycle days by caste
The honey bee life cycle days are the backbone of brood management. Every egg hatches after about 3 days; what differs between the castes is when the larva is capped and when the adult emerges (Ellis 2015; FAO):
| Caste | Egg hatches | Cell capped | Adult emerges | Days as a larva | Days capped |
|---|---|---|---|---|---|
| Queen | day 3 | day 8 | day 16 | 5 | 8 |
| Worker | day 3 | day 9 | day 21 | 6 | 12 |
| Drone | day 3 | day 10 | day 24 | 7 | 14 |
Sources: FAO Bulletin 68 (queen larvae sealed five days after hatching, workers six, drones seven) and Ellis 2015 (16, 21 and about 24 days). Traynor (2018) gives the worker's version as easy arithmetic: "3 days as an egg + 6 days as a larva + 12 days underneath a capping = 21 days until adult."
These are the same day counts used on the worker bee, queen bee and drone bee pages and the bee life cycle chart, so a date you calculate here lines up with every other bee tool on the site.
Honey bee brood calculator in three modes
- Egg date — you know (or can estimate) when the eggs were laid. You get the hatching, capping and emergence dates; for a queen, also her first flights and earliest egg laying.
- What I see on the frame — you don't know the date, but you can see the stage. The calculator works backwards to the likely egg-laying dates and forwards to the emergence window.
- A queen cell — you found a queen cup or cell. You get the likely emergence window, mating flights and the day to check for eggs.
Honey bee brood stages: egg, open brood, capped brood
Beekeepers sort the honey bee brood stages into three groups you can see on a frame: eggs, open (uncapped) brood — the larvae — and capped (sealed) brood, which holds the pre-pupae and pupae. FAO puts the scale of it at about 5,000 eggs and 25,000–30,000 developing young in an average colony at any one time, about 10,000 of them larvae being fed by the workers.
Stages of honey bee brood on a frame
These are the five stages of honey bee brood the calculator recognises, with the egg's age each one implies (days since the egg was laid):
| What you see | Worker | Drone | Queen |
|---|---|---|---|
| Egg standing upright | egg 0–1 days old | egg 0–1 days old | egg 0–1 days old |
| Egg tilted or lying down | egg 1–3 days old | egg 1–3 days old | egg 1–3 days old |
| Young larva | egg 3–6 days old | egg 3–6 days old | egg 3–5 days old |
| Large larva | egg 6–9 days old | egg 6–10 days old | egg 5–8 days old |
| Capped (sealed) cell | egg 9–21 days old | egg 10–24 days old | egg 8–16 days old |
The egg ages come from the shared day counts above, plus Traynor's (2018) observation that an egg "stands erect for about 24 hours, then slowly tips over". The split of the larval period into "young" and "large" larvae at its halfway point is our simplification — it gives a range that is easy to use at the hive.
Open vs capped brood
Open brood is everything still being fed: eggs and larvae in uncapped cells. Capped brood is sealed under a slightly porous wax capping (Traynor 2018). The distinction matters because it tells you about the queen's recent work: open worker brood shows she was laying within roughly the last 9 days (a worker larva is capped on day 9), while capped worker brood was laid between about 9 and 21 days ago. The two also look different: "the cappings for worker brood are pretty flat, covering the cell at much the same level as the cell walls," while "drone brood cappings … are shaped like the head of a bullet" (Traynor 2018).
Bee larvae stages and feeding
A honey bee larva grows through five bee larvae stages, called instars; it sheds its skin at the end of each one (Traynor 2018). Traynor's description of what you see:
- Just hatched: "a tiny c-shaped white grub barely visible at the bottom of the cell", floating in a pool of brood food that looks "a little like egg white just as it starts to cook".
- Third instar: "the larva fills almost the entire base of a cell."
- Fifth instar: "so big and fat, it looks like it's crunched into the cell ready to spill out" — healthy larvae now "look plump, white, and glisten", and the workers start building the wax capping.
Nurse bees feed each larva "over 100x per day" (Traynor 2018). What they feed depends on the caste (FAO):
- Days 1–3 of larval life: every larva gets royal jelly ("bee milk") from the nurse bees' glands.
- After that: worker and drone larvae get a mixed food of honey and pollen; a larva being raised as a queen keeps getting royal jelly for her whole five-day larval life.
- Why it matters: because the switch happens at three days, "queens can be reared from any worker larvae younger than three days" — which is how a colony replaces a queen in an emergency (FAO).
Bee development stages at a glance
The bee development stages in time order, for a worker: egg (days 0–3), larva on royal jelly (days 3–6), larva on honey and pollen (to day 9), capping and cocoon spinning, pupa (to day 21), emergence. For drones the larval period runs a day longer and the capped period two days longer; for queens both are shorter.
Honey bee pupa: what happens under the capping
Once the cell is capped, the larva "stretches out in the cell and spins a cocoon" (Traynor 2018) and becomes a honey bee pupa. Traynor calls this "the hidden stage of bee development": about 12 days for a worker, during which "the developing bee metamorphoses, changing its entire body plan from a white grub into the segmented worker bee with a head, thorax, and abdomen."
How long are bees capped?
For the three castes, the capped period is:
- Queen: 8 days (capped day 8, emerges day 16).
- Worker: 12 days (capped day 9, emerges day 21).
- Drone: 14 days (capped day 10, emerges day 24).
The longer drone capping is also why parasitic mites breed so well in drone cells — see the varroa mite life cycle.
When will capped brood emerge?
Capped worker brood will emerge within 12 days at most — sooner if it was capped a while ago. The calculator's "capped" option gives that window from today. On the frame, you can sometimes spot the bees that are about to come out: "right prior to emergence, the worker bee thins the capping from inside", so those cappings "appear a tinge darker" (Traynor 2018). Freshly emerged cells have ragged edges that the bees smooth over before the queen lays in them again.
Brood temperature and chilled brood
The day counts assume brood kept at the colony's normal nest temperature. Developing bees need about 33–36 °C, and the adults hold the brood nest there by clustering, shivering and fanning (Seeley 1985, via deJong 2024). In winter, the centre of the cluster is kept at about 95 °F (35 °C) whenever there is brood (UF/IFAS). Brood that gets chilled — for example when a frame is left out of the hive on a cold day, or a small colony can't cover all its brood — develops more slowly, so its real dates slip later than the calculator's. That is one more reason UF/IFAS advises opening hives in cold weather only briefly, on days above 50 °F (10 °C).
Emergency queen cells: the arithmetic
When a queen dies suddenly, "the workers reconstruct a few worker cells, containing larvae younger than three days, into queen cells and continue to feed the larvae with royal jelly" (FAO). Those larvae hatched from eggs laid 3–6 days earlier, and a queen emerges on day 16 from her egg, so an emergency queen can appear about 10–13 days after the colony starts raising her — our arithmetic from FAO's day counts. Use the queen cell mode to date the cells you find.
Using the dates at the hive
- Is there a queen? Upright eggs mean one was laying within about the last day; eggs of any kind mean within about 3 days (Traynor 2018; Ellis 2015). No eggs and no young larvae suggests no laying queen for several days.
- When will the next bees come out? The oldest capped worker brood is at most 12 days from emerging, so a frame of capped brood is a predictable wave of young bees — useful when planning to move or combine frames.
- Drone brood timing. Colonies rear drones in late spring and early summer (FAO), and a drone needs 24 days from egg to adult, so drone brood you see capped today becomes flying drones within about two weeks.
- Keep notes. Writing down what you saw — eggs, larvae, capped brood, queen cells — and the date makes the next inspection easier to interpret, because brood moves on a fixed schedule.
Reading a brood frame
Brood is the best evidence you have of the queen's health. These basics come from the extension and research sources we use:
Brood pattern basics
- A good pattern "shows capped brood in the center, with pollen and honey surrounding the brood" (UF/IFAS). The queen "tends to lay a central patch of eggs, which her workers can keep warm, then expand the brood nest in concentric arches" (Traynor 2018), so brood of the same age sits together.
- A spotty pattern "suggests a failing or missing queen or a colony with potentially bad health"; colonies with patterns like that in early autumn "often do not survive winter" (UF/IFAS).
- Eggs mean a queen was laying recently. "If you can spot eggs in your hive, you can tell if your colony is 'queenright' even if you don't spot the queen" (Traynor 2018). An upright egg was laid within about the last day.
- Drone cells are larger and "most commonly are found on the edges and bottom of frames" (Traynor 2018).
Laying worker signs
If a colony loses its queen and can't raise a new one, some workers start laying. Their eggs are unfertilized, so they become drones. The giveaway is in the cells: "When workers lay eggs there will usually be multiple eggs per cell, deposited on the cell wall, as their abdomens are too short to reach the cell bottom" (Traynor 2018). A new queen can also occasionally lay two eggs in a cell while she is "still getting the hang of egg-laying" — so look for the overall pattern, not one cell. Bullet-capped drone brood scattered through worker comb is a related warning sign of a queen running out of stored sperm (UF/IFAS, on the queen bee page). Contact your local beekeeping association or Extension apiarist if you suspect a laying-worker colony.
Queen cell timeline
The queen cell mode uses the same day counts as the queen bee page's timeline (FAO; Ellis 2015):
| Queen cell | Egg age (days) | Virgin queen emerges |
|---|---|---|
| Queen cup with an egg | 0–3 | in 13–16 days |
| Open queen cell with a larva | 3–8 | in 8–13 days |
| Capped queen cell | 8–16 | in 0–8 days |
After emerging, a virgin queen makes her first orientation flight about five days later, then mating flights; she starts laying about three days after her last mating flight, so the earliest eggs come about day 24 from the original egg. If there are still no eggs about a month after she emerged, she may only be able to lay drone eggs (FAO). Weather that stops mating flights pushes every later date back.
How this brood calculator works
- Day counts: hatching on day 3; capping on day 8, 9 or 10; emergence on day 16, 21 or 24 for queens, workers and drones (Ellis 2015; FAO). The same shared data feeds the bee life cycle chart and the worker, queen and drone pages.
- Egg-date mode: adds those days to the date you enter and shows which stage the brood is in today. For queens it also adds FAO's orientation-flight (day 21), earliest-laying (day 24) and "check for eggs" (day 46) milestones — the same as the queen bee page.
- Stage mode: converts the stage into a range of egg ages (table above) and subtracts it from today for the egg dates, then adds the remaining time for the capping and emergence windows.
- Queen cell mode: a cup with an egg means the egg is 0–3 days old, an open cell with a larva 3–8 days, a capped cell 8–16 days.
Development runs at the brood nest's normal temperature; chilled brood develops more slowly, and the dates are typical rather than exact. This is an educational tool — for colony health decisions, follow your local beekeeping association or Extension apiarist.
Frequently asked questions
How many days is the honey bee life cycle?
From egg to adult: 16 days for a queen, 21 for a worker and about 24 for a drone (Ellis 2015; FAO).
What are the honey bee brood stages?
Eggs, open brood (larvae in uncapped cells) and capped brood (pre-pupae and pupae under a wax capping).
How long are bees capped?
Queens about 8 days, workers 12 and drones 14 — from capping on day 8, 9 or 10 to emergence.
When will capped worker brood emerge?
Within 12 days of capping. Cappings that look slightly darker are being thinned from inside by bees about to emerge (Traynor 2018).
How can I tell how old an egg is?
An egg standing upright is under about a day old; one tilted or lying flat is one to three days old. All eggs hatch after about three days (Traynor 2018; Ellis 2015).
What is the difference between open and capped brood?
Open brood is eggs and larvae still being fed in uncapped cells; capped brood is sealed under wax while the bee develops into an adult.
What do drone cappings look like?
Domed, "shaped like the head of a bullet", over larger cells often on the edges and bottom of frames; worker cappings are flat (Traynor 2018).
What are the signs of a laying worker?
Several eggs in one cell, stuck to the cell walls instead of the bottom, and drone brood in worker cells (Traynor 2018).
How long until a queen cell hatches?
The queen emerges on day 16 from the egg; a capped queen cell has up to 8 days to go (FAO; Ellis 2015).
When does a new queen start laying?
About day 24 from the egg at the earliest — orientation flight five days after emerging, mating flights, then laying three days later (FAO).
How many larval stages does a honey bee have?
Five instars; by the third the larva fills most of the cell floor, by the fifth it is ready to be capped (Traynor 2018).
What does a good brood pattern look like?
Capped brood in the centre with few empty cells, ringed by pollen and honey; a spotty pattern suggests a queen problem (UF/IFAS; Traynor 2018).
For education. Bees are pollinators — never spray a swarm or a colony. For a swarm or bees in a wall, contact a local beekeeper, a certified bee-removal specialist or your Extension office (UGA Extension; Mississippi State). Follow your local apiculture or Extension guidance on varroa and colony care. If a sting causes trouble breathing, swelling of the face or throat or faintness, call emergency services.