Formula
Monthly saving = (goal − future value of what you have) × i ÷ [(1+i)n − 1], with i the monthly rate.
FAQ
How much a month to save $20,000 in 2 years?
About $716 a month if you already have $2,000 and earn 4% APY.
Sources (checked Nov 6, 2026): Standard annuity formula.