The mirror image of a compound growth projection: instead of projecting forward from today, this discounts a known future amount back to what it's worth right now, given up some expected rate of return in the meantime. The discount rate you pick matters more than the math itself — a higher assumed return shrinks today's equivalent value faster.

🇵🇹 Useful for comparing a lump sum offered now against a promised future payment — an early-retirement package, a deferred bonus, or deciding whether cashing in Certificados de Aforro before maturity is worth it. The result depends entirely on the discount rate you choose, so try more than one scenario rather than trusting a single number.