Junior ISA worked example

Junior ISA calculator by starting age

Starting earlier matters because the same monthly payment gets more years to compound before the child turns 18.

Static example £100/month model Updated

Short answer

At £100/month, starting from birth projects about £34,000 by 18

Starting at age 5 projects about £21,525. Starting at age 10 projects about £11,651. Same monthly contribution, very different runway.

Starting age Contributed Projected at 18 Today's money
Age 0£21,600£34,040£21,825
Age 5£15,600£21,525£15,615
Age 10£9,600£11,651£9,563

Educational projection only. This is not financial advice or a promise of investment returns.

Compare two children with different ages