How We Calculate: Formulas, Data Sources and Review Process

By TheWebCalc · Last reviewed: October 20, 2026

Every number on this site comes from a formula you can see, check and repeat. This page publishes the exact maths behind our Grow a Garden calculators, where the multipliers and pet values come from, and how we review and correct them — so you never have to take a result on trust.

The Fruit Value Formula

Our homepage fruit calculator prices a crop in four steps. It starts with the crop's base price, adjusts for size, then applies the variant and the combined mutation bonus:

Base price and normal weight. Every crop has a base sell price and a normal (base) weight. Both are stored as plain values in the page, so anyone can view them and check our maths.

Weight. Size counts twice over — literally. Value grows with the square of the size difference, so a fruit at twice its normal weight is worth about four times as much before any bonus, and one at three times the size is worth about nine times as much.

Variant. Normal is ×1, Gold multiplies value by 20, and Rainbow multiplies it by 50.

Quantity. If you enter more than one fruit, the per-fruit result is multiplied by the quantity.

Here is the worked example from our homepage, with every step shown. A Watermelon has a base price of 2,708 and a base weight of 7.3 kg. At 14.6 kg it is twice the base size:

Try the exact numbers in the fruit tab on the homepage and you will get the same result — about 1.08M sheckles. Our calculator guide walks through the same maths step by step for beginners.

How Mutations Combine

A fruit can carry more than one mutation, and in our calculator the bonuses are added together rather than multiplied. Each bonus has 1 subtracted, those amounts are added up, and 1 is added back:

So a fruit with Wet (×2) and Chilled (×2) gets 1 + 1 + 1 = ×3, not ×4. This keeps estimates realistic and stops small bonuses from inflating the total. One rare mutation usually beats several common ones.

The calculator's full set covers nine mutations — Chocolate and Moonlit also sit at ×2. These are the multipliers our calculator uses, based on in-game values and community documentation. Games change how stacking works, so multipliers can change with updates, and we re-check them when they do.

Grow a Garden 2 does not stack mutations the same way, so the sequel's calculators on our Grow a Garden 2 wiki use their own base values and rules, kept separate from the ones on this page.

Pet Weight (Pet KG)

Pets use a different formula. A pet's weight rises steadily as it levels up:

A dog with a 3 kg base weight reaches 3 × (1 + 50 ÷ 10) = 18 kg at level 50, and 3 × (1 + 100 ÷ 10) = 33 kg at level 100. The tool also works backwards: enter a target weight and it shows you the level you need to reach.

As our calculator guide states openly, this is a simplified model. The game may round weights or use a different curve for some pets, so treat the result as a planning estimate and confirm the actual weight in game.

Pet Values and Trade Fairness

Crop prices come from the game. Pet trade values do not — the game sets no official pet prices. Pet values are community estimates shaped by what players actually accept in trades, and they move with rarity, weight and age, mutation, and demand.

That is why our trade calculator does not hide a price list of our own. You enter each pet's value from a current community value list, and the tool does the maths in the open. A mutation is applied as a multiplier:

If your value list shows a flat bonus instead of a multiplier, add the bonus to the pet's value and leave the multiplier at 1. Never apply both to the same pet, because that double counts the bonus.

Add up both sides and compare the totals. This calculator treats a trade as fair when the two totals are within about 5% of each other, measured against the larger total. A bigger gap shows which side is ahead — and rare or in-demand pets can justify a small premium.

The worked example on the trade calculator page uses illustration numbers, not real prices: your side totals 220 (a pet at 120 × 1, plus one at 50 × 2 = 100) against 230 on their side. The gap of 10 is about 4% of the larger total, so it falls inside the fair range.

TheWebCalc does not publish or guarantee pet prices, and no calculator can predict demand. Use a current list for every important trade.

Where Our Numbers Come From

Our base prices, base weights, mutation multipliers and pet base weights come from two sources: observation inside the game itself, and community-verified values and documentation, cross-checked against each other and reviewed against game updates.

Those numbers are stored as plain values in our pages, and the formulas are published on this page and in our guide, so you can verify any result yourself. Where sources disagree, we say so on the page and use the figure we can verify in game.

How We Review and Update

The game changes crop prices, mutations and pet stats during updates, so after each game update we re-check the formulas and base values the calculators use, and fix any page whose numbers have moved. We also refresh base values whenever we spot a change between updates.

Our pages show when they were last updated, and this page — like our main calculator pages — carries a "Last reviewed" date, so you can see when the numbers were last checked even when a review finds nothing to change. If a page's date looks old, treat its numbers as a guide and double check in game.

Corrections

Spotted a wrong number? Tell us through the Contact page and say which crop, pet or page it appears on. We check every report against the game and fix confirmed errors. The correction route is part of how this site stays accurate, so reports are genuinely welcome.

Who Runs TheWebCalc

TheWebCalc — the team behind GAG Calc — builds and maintains every calculator on this site. We are players who wanted to check what a crop or pet was worth before selling or trading it, without guessing. You can read more about the project on our About page.

GAG Calc is a fan-made project. It is not affiliated with, endorsed by or connected to Roblox Corporation or the developers of Grow a Garden, and it is not an official price source.

What These Numbers Cannot Do

A calculator estimates a sell price. It cannot predict what another player will pay, because trade value depends on demand, which changes all the time. It also cannot protect you from scams: only trade through the game's own trade window, and check the final offer on screen before you accept. Used with those limits in mind, the numbers here will stop most bad deals before they happen.