A lump-sum fixed deposit (整存整取) pays simple interest: the interest at maturity is I = P × r × t, where P is the principal, r the annual rate as a decimal and t the term in years, so the total payout is P × (1 + r × t). Annual compounding instead credits interest once a year and lets it earn interest too: the total payout is P × (1 + r)^t and the interest is that amount minus P.
For the same rate and term, compounding always yields at least as much as simple interest, and the gap widens with longer terms. This tool shows both methods side by side along with the exact extra interest compounding earns. All calculations run locally in your browser; nothing is uploaded.