Opening a recurring deposit earning 6% while carrying a credit card balance charging 20% means you're guaranteed to lose money on the spread — and yet this exact combination is extremely common, often for reasons that have nothing to do with the math
A frequent personal-finance question: "should I put my monthly savings into a recurring deposit, or use it to pay down existing debt?" When the debt's interest rate exceeds the RD's interest rate (which is almost always true when comparing an RD against credit-card or high-interest personal-loan debt) — the mathematically guaranteed outcome favors debt repayment. But the reasons people still choose to save alongside (or instead of) aggressively repaying debt are worth examining, because some of them are legitimate, not just "bad math."
The basic mathematical comparison
RD earning 6% annually vs. credit card debt charging 20% annually:
Every dollar directed toward the RD earns 6% per year. Every dollar directed toward paying down the 20% debt avoids 20% per year in interest charges.
"Avoiding a cost" and "earning a return" are economically equivalent for this comparison — a dollar that avoids 20% interest is exactly as valuable as a dollar that earns 20% interest (in terms of your net financial position) — and 20% (interest avoided) is greater than 6% (interest earned) — so, purely mathematically, paying down the 20% debt is the better use of each available dollar, by a substantial margin (a 14-percentage-point gap, in this example).
This comparison holds regardless of the RD's specific terms (tenure, compounding frequency) — as established in previous articles, RD returns, while meaningfully affected by compounding frequency, don't typically approach the kind of rates that would make 6% competitive with 20% — the gap is generally large enough that the specific mechanics of RD compounding don't change the conclusion.
Reason 1: emergency fund considerations — liquidity has value beyond "return"
A recurring deposit (or, more commonly for this purpose, a separate savings/liquid account) serving as an emergency fund provides a kind of value that isn't captured by "interest rate" comparisons alone: access to funds without needing to borrow (potentially at even higher rates) for unexpected expenses.
If someone has zero savings and is aggressively paying down debt — an unexpected expense (medical bill, car repair, job loss) might force them to borrow (potentially at a high rate — a new credit card charge, a payday loan in some circumstances) to cover the unexpected cost, because there's no "buffer" of savings to draw from instead.
The "cost" of not having an emergency fund isn't captured by comparing "RD rate" vs "debt rate" directly — it's a risk (the possibility of needing to borrow at a high rate, which might not happen, but could) — financial planning guidance commonly suggests maintaining some minimal emergency fund even while carrying high-interest debt, specifically to mitigate this risk — though the "right" size of such a fund, while carrying high-interest debt, is a genuinely debated question (some guidance suggests a very small "starter" emergency fund — e.g., covering one month's essential expenses — while directing the majority of available funds toward high-interest-debt repayment, with a larger emergency fund being built up after high-interest debt is cleared).
Reason 2: psychological/behavioral factors — "seeing savings grow" as motivation
Some people find that seeing a savings balance grow (even modestly, via an RD) provides motivation/reinforcement that supports their overall financial discipline — including, potentially, discipline around not accumulating further debt.
This connects to the debt snowball discussion from a previous article — just as snowball (mathematically "suboptimal" ordering of debt repayment) can outperform avalanche in practice due to motivational factors — splitting some available funds toward savings (even at low return), alongside debt repayment, might, for some individuals, support better overall financial behavior than directing 100% toward debt repayment and 0% toward visible, growing savings — if that visible savings growth is part of what keeps someone engaged/motivated with their broader financial plan.
This is genuinely individual — some people find "all available funds go to debt, until it's gone, then redirect to savings" perfectly sustainable and motivating in its own right ("watching the debt shrink" serving the same motivational role as "watching savings grow" would for someone else) — there's no universal answer; the relevant question is "what approach will I actually sustain," which only the individual can really assess.
Reason 3: contractual/structural commitments — RDs already in progress
A recurring deposit, once started, typically involves a commitment to make regular deposits over a fixed tenure (covered in previous articles) — premature closure/withdrawal often involves a penalty (reduced interest rate applied retroactively, or a fee).
If someone already has an RD in progress when they take on high-interest debt (e.g., an unexpected expense led to new credit-card debt, after the RD was already established and partway through its tenure) — breaking the RD early to redirect funds toward the debt might trigger a penalty that reduces the RD's effective return below even its already-modest stated rate — in which case, the comparison isn't "6% RD vs 20% debt" but "[RD's rate, reduced by the early-closure penalty] vs 20% debt" — the mathematical conclusion (pay down the debt) likely still holds (the gap is large enough that even a penalty-reduced RD rate is probably still below 20%) — but the magnitude of the benefit from breaking the RD early needs to account for the penalty, not just the RD's originally-stated rate.
When the comparison is closer: RD rates vs low-interest debt
The "obviously pay down debt" conclusion becomes less clear-cut when comparing an RD against lower-interest debt — e.g., a mortgage at, say, 4-5% interest (in some markets/periods) compared against an RD at similar or even somewhat lower rates.
In these cases, the gap between "RD rate" and "debt rate" may be small, zero, or even negative (RD rate higher than mortgage rate, in some rate-environment scenarios) — at which point, factors beyond the headline rate comparison become more influential: tax treatment (in some jurisdictions, mortgage interest may be tax-deductible, effectively reducing its "real" cost below the stated rate; RD interest may, conversely, be taxable, reducing its "real" return below the stated rate — both effects narrowing, or potentially reversing, the "gap" that exists at the headline, pre-tax rate level), liquidity preferences, and the broader financial-planning considerations discussed above — for low-interest debt specifically, the "obviously pay down debt" conclusion that applies strongly for high-interest (credit-card-level) debt is much less clear-cut, and "both" (some savings, some extra debt repayment) is a commonly-recommended balanced approach for this lower-interest-rate scenario.
How to use the RD Calculator on sadiqbd.com
- Calculate the RD's effective return — including, if relevant, any early-closure penalty if you're considering breaking an existing RD
- Compare against your highest-rate debt's interest rate (using the EMI/Loan Planner calculators for the debt side) — for high-interest debt (credit cards, typically 15%+ in many markets), the gap is usually large enough that the conclusion ("prioritize debt repayment") is clear
- For lower-interest debt (mortgages, some personal/auto loans in favorable rate environments): the comparison is closer, and factors beyond the headline rates (tax treatment, liquidity needs, behavioral preferences) become more relevant to the decision
Frequently Asked Questions
Is it ever "smart," purely financially, to keep an RD running while carrying high-interest debt? Purely on the interest-rate math, generally no — for high-interest debt specifically (well above typical RD rates), directing available funds toward debt repayment will, in expectation, leave you with more money than the RD-plus-debt combination. The "reasons" discussed above (emergency fund, motivation, existing commitments) represent considerations beyond the pure interest-rate math — they're not "the math is actually different than it appears"; they're "there are other, non-interest-rate factors that might reasonably influence the decision for a specific individual, even if the pure interest-rate comparison favors debt repayment."
Is the RD Calculator free? Yes — completely free, no sign-up required.
Try the RD Calculator free at sadiqbd.com — calculate recurring deposit returns and compare against your debt's interest cost.
