Using a Future Value Table (HSC SSCE Mathematics Standard): Revision Notes
Using a Future Value Table
What is a future value table?
A future value table is a practical tool that simplifies annuity calculations. Instead of using complex formulas repeatedly, the table provides pre-calculated values that show what $1 will grow to when invested regularly over different time periods at various interest rates.
The table shows the future value of an annuity where $1 is invested at the end of each period, with interest compounded per period. These pre-calculated values act as multiplication factors that you can use with your actual investment amount.
For example, if you look up the value for 6 periods at 6% interest per period, you'll find 6.9753. This means that investing $1 at the end of each period for 6 periods at 6% interest will grow to $6.9753.
Understanding the future value table structure
Future value tables are organized in a grid format:
- Rows represent the number of time periods (such as years, months, or quarters)
- Columns represent the interest rate per period (as a percentage)
- Intersection values are the multiplication factors you'll use in your calculations
Here is an example of a future value table:
| Period | 1% | 2% | 3% | 4% | 5% | 6% |
|---|---|---|---|---|---|---|
| 1 | 1.0000 | 1.0000 | 1.0000 | 1.0000 | 1.0000 | 1.0000 |
| 2 | 2.0100 | 2.0200 | 2.0300 | 2.0400 | 2.0500 | 2.0600 |
| 3 | 3.0301 | 3.0604 | 3.0909 | 3.1216 | 3.1525 | 3.1836 |
| 4 | 4.0604 | 4.1216 | 4.1836 | 4.2465 | 4.3101 | 4.3746 |
| 5 | 5.1010 | 5.2040 | 5.3091 | 5.4163 | 5.5256 | 5.6371 |
| 6 | 6.1520 | 6.3081 | 6.4684 | 6.6330 | 6.8019 | 6.9753 |
Key point: The intersection value includes both the total of all your contributions AND the compound interest earned. This is why the value for period 1 is always 1.0000 (no interest has been earned yet on a single contribution).
Steps to use a future value table
Follow these three steps when working with future value tables:
Step 1: Identify the number of time periods and the interest rate per period
Step 2: Find where the period row and interest rate column meet in the table (the intersection value)
Step 3: Multiply the intersection value by the regular contribution amount
Adjusting for different compounding frequencies
When interest is compounded more frequently than annually, you must adjust both the number of periods and the interest rate:
Number of periods:
Interest rate per period:
Common compounding frequencies:
- Annually: 1 time per year (no adjustment needed)
- Semi-annually (six-monthly): 2 times per year
- Quarterly: 4 times per year
- Monthly: 12 times per year
- Biannually: 2 times per year (same as semi-annually)
Always check whether the interest rate given is per annum (p.a.) or per period. If it's per annum and compounding is more frequent than yearly, you must divide the rate by the compounding frequency.
Calculating future value
To calculate the future value of regular contributions, use this formula:
Where:
- = future value of the annuity
- Intersection value = the number from the table
- Contribution amount = the regular payment made each period
Worked Example 1: Annual compounding
Question: Calculate the future value of $34,000 invested per year for 3 years at 5% p.a. compounded annually.
Solution:
- Identify the period: years
- Identify the interest rate: per year
- Find the intersection value from the table for period 3 and interest rate 5%
- Intersection value is
- Apply the formula:
Answer: The future value is $107,185
Worked Example 2: Six-monthly compounding
Question: Calculate the future value of $5,000 invested per half-year for 2 years at 6% p.a. compounded six-monthly.
Solution:
- Calculate the number of periods: (2 years × 2 periods per year)
- Calculate the interest rate per period: per half-year
- Find the intersection value from the table for period 4 and interest rate 3%
- Intersection value is
- Apply the formula:
Answer: The future value is $20,918
Worked Example 3: Monthly compounding
Question: What is the future value of an investment of $300 per month for 3 months at 24% p.a. compounded monthly?
Solution:
Using this future value table:
| Period | 1.0% | 1.5% | 2.0% | 2.5% | 3.0% | 3.5% | 4.0% |
|---|---|---|---|---|---|---|---|
| 1 | 1.000 | 1.000 | 1.000 | 1.000 | 1.000 | 1.000 | 1.000 |
| 2 | 2.010 | 2.015 | 2.020 | 2.025 | 2.030 | 2.035 | 2.040 |
| 3 | 3.030 | 3.045 | 3.060 | 3.076 | 3.091 | 3.106 | 3.122 |
| 4 | 4.060 | 4.091 | 4.122 | 4.153 | 4.184 | 4.215 | 4.246 |
- Number of periods: months
- Interest rate per period: per month
- Find the intersection value for period 3 and interest rate 2%
- Intersection value is
- Apply the formula:
Answer: The future value is $918
Worked Example 4: Quarterly compounding
Question: What is the future value of an investment of $15,000 per quarter for 1 year at 12% p.a. compounded quarterly?
Solution:
- Number of periods: (1 year × 4 quarters per year)
- Interest rate per period: per quarter
- Find the intersection value for period 4 and interest rate 3%
- Intersection value is
- Apply the formula:
Answer: The future value is $62,760
Finding the payment or contribution amount
Sometimes you know the desired future value and need to find what regular payment is required. This is a reverse calculation where you rearrange the formula:
Where:
- = payment or contribution per period
- = desired future value
- Intersection value = the number from the table
Worked Example 5: Finding annual payment
Question: Find the payment per period of an annuity with a future value of $76,713 at 3.5% p.a. compounded annually for 4 years.
Solution:
- Number of periods: years
- Interest rate: per year
- Find the intersection value for period 4 and interest rate 3.5%
- Intersection value is
- Set up the equation:
- Divide both sides by the intersection value:
Answer: The payment required is $18,200 per year
Worked Example 6: Finding biannual payment
Question: Find the payment per period of an annuity with a future value of $6,105 at 7% p.a. compounded biannually for 1 year.
Solution:
- Number of periods: (1 year × 2 periods per year)
- Interest rate per period: per period
- Find the intersection value for period 2 and interest rate 3.5%
- Intersection value is
- Set up the equation:
- Divide both sides by the intersection value:
Answer: The payment required is $3,000 per half-year
When finding the payment amount, always check your answer makes sense. The total of all payments should be less than the future value (because the future value includes interest earned).
Key Points to Remember:
- Future value tables simplify annuity calculations by providing pre-calculated multiplication factors for $1 invested regularly
- To use the table: identify the period and interest rate, find the intersection value, then multiply by the contribution amount
- When compounding occurs more frequently than annually, adjust both the number of periods (multiply by frequency) and the interest rate (divide by frequency)
- To calculate future value:
- To find the required payment:
- Always ensure your period count and interest rate match the compounding frequency specified in the question