How much will £100 a month in a stocks and shares ISA grow?

At 5% growth a year after 0.5% fees, about £15,029 after 10 years, £38,316 after 20 and £74,398 after 30. You'd have paid in £12,000, £24,000 and £36,000. Returns aren't guaranteed.

About £47,780 after 20 years, and £106,048 after 30.

Yes. Small regular amounts add up because growth compounds over time, and many platforms let you start from as little as £25 a month. A cash ISA is usually better for money you'll need within about five years.

At 5% growth after fees, £200 a month could grow to about £76,633 in 20 years, and £500 a month to about £191,582.

£100 a month in a cash ISA paying 4% would reach about £36,384 after 20 years, against £38,316 in stocks and shares at 5%. Cash is steadier; investments usually grow more over the long term but can fall.