Descaling Calculator
"Every three months" is a number printed for an average machine on average water. Yours is neither. Three questions gets you an interval that reflects what you actually drink and what actually comes out of your tap.
How this is calculated
Every machine family starts from a baseline interval — the point most manufacturer guidance lands on for a moderately hard supply at around two drinks a day. That baseline is then stretched or compressed by three multipliers.
| Factor | Effect |
|---|---|
| Machine baseline | Pump espresso machine — 90d · Super-automatic / bean-to-cup — 60d · Drip coffee maker — 120d · Pod / single-serve — 90d · Electric kettle — 150d |
| Water hardness | Scales inversely against 90 ppm. Very hard water roughly halves the interval; soft water roughly doubles it. |
| Usage | Scales inversely against 2 drinks a day. Scale deposits with volume of water boiled, not with time on the counter. |
| Filtration | An in-tank cartridge or filtered jug extends the interval by about 40%. Bottled or distilled water roughly doubles it. |
What this is, and what it is not
This is a working model based on how scale actually accumulates, not a manufacturer specification. If your manual gives a specific interval for your machine, or your machine has its own descale counter, follow that — and treat this as a sanity check on whether that number suits your water.