Potato Calculator

This calculator relies on fundamental mass-balance equations for mixtures containing solid dry matter and fluid water content. The total mass of a potato (old_mass) is divided into dry matter (dry) and water mass (old_water_mass). The core equations are expressed as:

old_mass = dry + old_water_mass

old_water_mass = old_water_perc * old_mass

new_mass = dry / (1 - new_water_perc)

By holding the dry weight constant while altering the water percentage, you can evaluate how dramatically the total mass shrinks, revealing the fascinating mathematics behind dehydration and paradox problems.

Let us walk through a classic scenario inspired by the potato paradox. Imagine you have a fresh batch of potatoes weighing 100 kg total, consisting of 99% water and 1% dry matter.

Step 1: Calculate the dry weight. Since water is 99% of 100 kg (99 kg), the remaining dry mass is 1 kg.

Step 2: Suppose the potatoes dry out slightly so that their water content drops to 98%. Using our formula, new_mass = dry / (1 - new_water_perc), we divide 1 kg by (1 - 0.98), which equals 0.02.

Step 3: The new total mass is 1 / 0.02 = 50 kg! Even though the water percentage decreased by only 1%, the total mass halved because the unchanging dry weight represents a larger fraction of the whole.

When working with moisture content calculations, always distinguish clearly between mass percentage and absolute weight. A tiny shift in percentage points at extreme moisture levels (like 99% versus 98%) creates massive fluctuations in total weight because the dry matter acts as an anchor. Double-check your input values to ensure consistent units (such as kilograms or pounds) before processing conversions or relative error rates.