Work out what private use of a company car costs you net per month: 2026 rates per drivetrain, the 18% rate up to € 30,000 list price for fully electric cars, your employee contribution and your marginal Box 1 rate — including the full 60-month projection for a car first registered in 2026.
The rate that applies at first registration is locked in for sixty months. An electric car registered in June 2026 keeps the 2026 regime through May 2031: 18% on the first € 30,000 of list price and 22% on the remainder. That lock-in is exactly why a calculation per month and per calendar year is more useful than a single annual figure — the first and last years are almost always partial ones.
The projection holds the 2026 rate, your salary and a single marginal rate constant across the whole term; it is a working-out of the locked-in situation, not a forecast of future tax rates. The 2027 comparison runs on the indicative percentages from the source (20% up to € 30,000, 22% above) and is labelled as such. Every report states the tool version and the dataset vintage the percentages come from, so the calculation stays exactly reproducible later.