Cash vs Installment Calculator

Enter product price, cash discount, and installment terms to see which option costs less overall.

Your purchase

Product price

Cash discount (%)

Number of installments

How to enter installments

Interest rateAnnual APR, compounded monthlyTotal costFinal amount you will pay in installments

Annual interest rate (APR)

Total installment cost

Your data is not stored. Everything runs in your browser.

Your result

Totals compared

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Estimate based on your inputs. Excludes card fees, taxes, insurance, or penalties. Not financial advice.

What this tool does

Stores often offer a cash discount and installments with or without interest. What matters for your wallet is total cost, not just the monthly payment. This calculator puts both sides on the same scale.

Why compare totals

A low installment can hide high interest. A small cash discount may not matter if you need cash flow. Seeing both totals helps you decide with numbers, not gut feeling alone.

When to use and when it falls short

Use it to compare product, service, or course offers with a known product price. It does not replace credit-card simulations with fees, or debt consolidation with variable rates.

How to read the result

Three main blocks:

Hero: difference in amount and which option is cheaper overall.
Scenarios: cash total and installment total, with the winner highlighted.
Details: assumptions used and calculation steps you can audit.

Practical tips

Use total-cost mode when the store already quoted the final installment amount, with fees baked in.
In rate mode, check whether interest applies to full product price or another financed amount.
Add enrollment fees, insurance, or card annual fees before comparing with cash.
If the gap is small, cash flow and emergency savings may matter more than the discount.

Limitations

Simplified model: fixed installments, monthly compounding from annual APR. No down payment, grace period, or inflation. Result is an educational estimate.

How we calculate

Cash = product × (1 − discount/100). Installments with rate use fixed-payment amortization. Installments with total use the amount you enter.

cash = product × (1 − discount/100)
installments = payment × n or entered total
difference = abs(cash − installments)Pcash=Plist(1−d100)M=Plist r(1+r)n(1+r)n−1,r=APR1200Pinst.=M⋅n or stated totalΔ=∣Pcash−Pinst.∣\begin{aligned}P_{\text{cash}}&=P_{\text{list}}\left(1-\dfrac{d}{100}\right)\\M&=P_{\text{list}}\,\dfrac{r(1+r)^n}{(1+r)^n-1},\quad r=\dfrac{\mathrm{APR}}{1200}\\P_{\text{inst.}}&=M\cdot n\ \text{or stated total}\\\Delta&=|P_{\text{cash}}-P_{\text{inst.}}|\end{aligned}Pcash​MPinst.​Δ​=Plist​(1−100d​)=Plist​(1+r)n−1r(1+r)n​,r=1200APR​=M⋅n or stated total=∣Pcash​−Pinst.​∣​

Fixed-payment formula matches standard loan amortization (annuity), documented in finance textbooks and spreadsheets.

Frequently asked questions

Does the result tell me which option to pick?

No. It shows which costs less overall with your numbers. Cash flow, emergency fund, and late-payment risk also matter in real decisions.

What if installments are interest-free?

Enter 0% in rate mode, or the installment total in total-cost mode. With no interest and no cash discount, totals usually match the product price.

When should I use total cost instead of rate?

When the store or bank already gave the final installment amount, with fees included. You avoid guessing interest that may bundle insurance or charges.

Is this financial advice?

No. It is a transparent comparison of totals. For large decisions or debt, talk to a qualified professional.