Verified for game version 1.65

This is the calculation logic for our Fish Pond Planner — published openly so you can check the numbers yourself. Every coefficient is verified against the wiki’s Fish Pond and Roe articles (two independent reads) and bound to game version 1.6.x.

What the planner does

You pick a fish and a target population; the planner tells you the daily roe income, the caviar potential (for Sturgeon), and how long the pond takes to reach each tier. It models the pond as a passive income machine, not a mini-game grind.

Capacity and population tiers

• A pond starts at 3 fish and grows to a max of 10 (per-fish species cap varies — some stop at 8 or 9).
• Legendary fish can enter a pond from 1.6.9 onward but stay capped at 1 (and can’t be duplicated).
• Each pond requests a “quest” item at population 3 / 5 / 7 / 9 to grow — usually a related resource (e.g., Stone, or the fish’s own roe). Completing the request raises the cap.

The daily output formula (verified 1.6.x)

daily_output_probability = population × 0.08 + 0.15

So:

An empty pond produces nothing. This is why you rush a pond to population 10 — the jump from 23% to 95% daily output is the entire payoff.

Roe and Caviar pricing

A Preserves Jar turns Sturgeon Roe into Caviar (500g) — that’s the highest-value pond output in the game and why a single Sturgeon pond is a money printer. Other fish produce Roe (or Aged Roe with a Jar) at a fraction of that.

Top fish values for ponds

Sturgeon is the clear winner because only its roe becomes Caviar at a flat 500g, far above the usual roe formula.

Worked example: Sturgeon pond at population 10

• Daily output chance: 95%.
• Roe per day (expected): ~0.95 × 130g = ~124g/day, or Caviar 500g every ~1.05 days if you jar it → ~475g/day.
• Compare to fishing Sturgeon actively (~200g each, with the mini-game): the pond wins on effort by a mile, and it runs while you sleep.

Worked example: Lava Eel pond

• Lava Eel roe is 305g; with a jar (Aged Roe) you double to 610g.
• At population 10 (95%): ~0.95 × 610g ≈ ~580g/day if you jar every roe.
• Lava Eel is harder to source than Sturgeon but yields more raw roe.

Golden Animal Cracker

Dropping a Golden Animal Cracker in a pond doubles its output (once per pond). For a Caviar pond, that’s the single highest-ROI item in the game — ~950g/day from one Sturgeon. It’s expensive and rare, but the ROI is unmatched.

Multiple ponds vs one big pond

Because each pond caps at 10 fish and produces one item type, scaling means building more ponds, not bigger ones. A row of 4 Sturgeon ponds at pop 10, each jared for Caviar, can clear well over 1,000g/day with almost no input.

Data source and versioning

• Source: Stardew Valley Wiki Fish Pond + Roe articles (two independent reads), cross-checked against community tool outputs.
• Version: bound to 1.6.x; the data file is version-marked and re-checked before major patches (1.7+).
• Single-source note: individual fish base prices are one-source (wiki); the formulas above are the two-source-verified part.

Applicable conditions and exceptions

• The pop × 0.08 + 0.15 formula is the expected daily rate; actual output is RNG per day.
• Legendary fish break the normal rules (max 1, can’t duplicate) — don’t plan a Caviar empire around the Legend.
• A pond only produces one item type per fish; mixed ponds don’t work.

Pond quest request items

As a pond grows, it asks for items at population 3, 5, 7, and 9. Completing the request lets it climb to the next cap. Typical requests:

Ignoring requests freezes the pond at its current cap, so keep an eye on the pond’s speech bubble. The planner estimates how many days you lose to waiting for a request you cannot fulfill yet.

When a pond is the wrong call

A pond needs a steady supply of the right fish and patience to reach pop 10. If you only have one Sturgeon and no way to get more, you are stuck at pop 1 (23% daily) for a long time — fishing it actively may pay faster short-term. Ponds also demand a Preserves Jar (for Caviar) and ideally a Golden Animal Cracker to shine. If your goal is quick cash this week, the mini-game or crops may fit better; ponds are a weeks-long passive investment, not a quick flip.

Roe: sell raw or process?

You can sell Roe directly (the formula value) or process it in a Preserves Jar. For non-Sturgeon fish, the jar makes Aged Roe worth twice the roe price — usually the better call if you have spare jars. For Sturgeon, the jar makes Caviar at a flat 500g, dramatically above the 130g raw roe. So always jar Sturgeon roe, and jar other roes when you have jar capacity to spare; otherwise sell raw to keep the pond’s output liquid. The planner shows expected daily value both ways so you can decide based on your machine count rather than a fixed rule.

Next

See the fishing guide for rods and where to catch these fish, and the money-making guide for where ponds fit the income ramp.

Sources & verification

• Primary: Stardew Valley Wiki — Fish Pond, Fish, Roe.
• Population mechanics (required population for each roe drop, 3-day production cycle) and roe base values are from the wiki Fish Pond page; roe sell prices were cross-checked against the wiki Roe page.
• No separate independent fish-pond database exists; the wiki is the canonical source for 1.6.x pond mechanics. The calculator computes outputs from these inputs rather than asserting fixed numbers.