Here is how SGB Analyzer calculates the numbers in the SGB table. All prices are per unit (1 gram). Price means the seller's ask price, which can differ from the last traded price.

Fair value

Fair value = today's gold price + present value of remaining interest.

Present value means what future interest is worth today. We discount those payments using the selected annual discount rate; the gold price itself is added without discounting.

For the exact calculation: PV of interest = C × (1 − (1 + i)^(-n)) / i, where C = issue price × annual coupon rate / 200, i = annual discount rate / 200, and n is the remaining half-yearly payment count. Enter rates as percentages, e.g. 2.5 for 2.5%.

Discount to fair value

Discount % = (fair value − ask price) / fair value × 100.

Example: fair value ₹10,500 and ask price ₹9,500 → 9.52% discount.

Discount to gold price

Gold discount % = (gold price − ask price) / gold price × 100.

Example: gold ₹10,000/gram and ask price ₹9,500 → 5% discount. This comparison excludes future interest. A negative discount means a premium.

Remaining interest

Each half-yearly payment = issue price × annual coupon rate / 200.

Multiply this by the remaining payment count for total remaining interest. Use the bond's coupon rate; interest is based on its issue price, rather than your purchase price.

Total yield and YTM

The table's Total Yield is a simplified annualized estimate:

Yield % = (((gold price + total remaining interest) / ask price)^(1 / years to maturity) − 1) × 100

It assumes gold stays at today's price and groups all remaining interest with the maturity proceeds. A full yield to maturity (YTM) accounts for when each payment arrives; CFA Institute explains this distinction.

These are estimates before taxes and trading costs. Actual returns depend on future gold prices and your purchase price.