The calculators are to be used as a guide to see if your goal is realistic and can be achieved in the timeframe you'd like.
Enter the details of your starting amount (current savings or investments), any contributions you can make per month, your end goal and the timeframe you need to achieve this. The results will indicate if the timeframe, risk profile and contributions will be sufficient to achieve your investment goal.
If the calculator indicates you will fall short of your goal, look at the inputs that are realistic for you to alter:
Starting amount:
You most likely cannot change the amount of savings you currently have
Monthly contribution:
Can you save more without putting your lifestyle under pressure? Or are you happy to make further lifestyle changes if you need to reach this goal if your timeframe cannot be altered?
Risk profile:
Do you need to move to a higher risk profile? Consider how comfortable with this you will be.
Timeframe:
In most cases of missing your investment goal it is the timeframe that will need to be altered. Starting amounts and contributions often cannot be changed unless you are able to get a higher starting balance due to recieving a lump sum or are willing to make further lifestyle changes to increase your savings.