The short version
A percentage saving is a ratio between two costs. Both of those costs are computed using the same electricity rate — whatever that rate happens to be. When you divide one by the other to get a percentage, the rate appears in both the top and bottom of the fraction, and cancels out. The percentage you see doesn't know or care what the rate was.
Showing the cancellation
Take a simple version of the formula behind this site's calculator:
Optimized = Hours × Load × TempFactor(26°C) × Rate
Savings % = (Current − Optimized) / Current
= Rate × (stuff) / Rate × (other stuff)
Every term that depends on your local electricity market — the rate itself, the currency, how the utility structures its pricing — multiplies both the "before" and "after" cost identically. Dividing them cancels it out completely. What's left is purely about hours, room size, and temperature — physics, not economics.
Why this matters more in this region than most people realize
Electricity pricing across tropical Asia is genuinely inconsistent between markets — not just in the number, but in how it's set. Malaysia restructured its entire residential tariff system in July 2025, replacing tiered block pricing with a base rate plus a monthly fuel-cost surcharge (capped at ±3 sen/kWh per month to limit sudden swings). The Philippines' largest utility revises rates monthly too, tied to wholesale energy prices and currency movements — a single month's peso depreciation pushed rates up noticeably in early 2026. Indonesia's state utility has rates fixed by government decision rather than a predictable formula — held flat through Q3 2026 by explicit policy choice, not a formula result. A dollar figure computed today in any of these markets can be stale within weeks. A percentage figure never goes stale, because it was never tied to the rate in the first place.
| Market | Rate-setting pattern |
|---|---|
| Singapore | Quarterly, single published rate |
| Malaysia | Base rate + monthly surcharge (±3 sen cap), restructured July 2025 |
| Philippines | Monthly, tied to wholesale spot prices |
| Indonesia | Government-set, not on a fixed schedule |
The takeaway
"Switching to Dry Mode saves about 35–45%" is a claim that survives contact with any tropical city's electricity market, because it was never a claim about that market to begin with. That's not a limitation of this site's approach — it's the reason a percentage-first calculator can credibly serve many markets from one shared set of numbers, without needing to track a dozen countries' tariff schedules to stay accurate.