At a 3.5% withdrawal rate you need €1,142,857 to draw €40,000/year. You'd reach it in 30.5 years, around age 63.

Coast FIRE: you'd need about €228,426 invested today to "coast" to your FIRE number by 65 with no further saving.

Real-terms estimate (today's money); ignores tax and sequence-of-returns risk. Educational, not advice.