Methodology

Every number on CardLens comes from one open calculation engine. This page explains it so you can reproduce any score by hand.

1. Your spend becomes buckets

Monthly spend in 14 categories is annualised. If you picked merchants (say Amazon and Flipkart under online shopping), 70% of that category is split equally between them and the rest stays generic. Each rupee lands in exactly one bucket – nothing is double counted.

2. UPI is counted once

The share of groceries, dining, commute and “everything else” you pay by UPI QR is split out. On RuPay cards linked to UPI it earns that card's UPI rate and cap. On every other card it is removed from card spend entirely, because you cannot pay UPI QR with it. It is never counted twice.

3. Recurring net savings

Net savings = reward value + recurring milestones + fuel surcharge waiver + lifestyle benefits you asked for + renewal bonus (only when the fee is actually charged) − renewal fee incl. 18% GST − forex markup incl. GST on international spend.

Effective savings rate = net savings ÷ total annual card spend × 100. Card spend excludes UPI-only rupees on non-RuPay cards.

4. First-year value is separate

Welcome benefits (at ~90% of voucher face value) and the joining fee are shown as a separate first-year figure. They never influence the recurring number or the score, so a big sign-up bonus cannot disguise a poor long-term card.

5. Score components and weights

ComponentWeightHow it is measuredWhy this weight
Net savings rate55%Effective rate ÷ 6% ceiling, capped at 100. Negative → 0.Money is what most people mean by “best card”. We moved 5 points from the brief's 60% to a new fee-safety component so a card that only breaks even at a waiver threshold you barely reach is penalised.
Usable lounge access15%Visits you can actually use (entitlement, spend condition met, capped at your stated need; international counts double) ÷ your need.Lounges matter only to the extent you fly – so the metric is coverage of your need, not raw entitlement. If you need none, the weight is redistributed.
Redemption flexibility10%Card rating 1–5, adjusted for your reward preference (cashback lovers get 100 for auto-credit cards; miles collectors for transferable currencies).Points you never redeem are worth zero.
Lifestyle fit10%Share of the lifestyle benefits you ticked that the card offers.Only benefits you asked for count; if none selected the weight is redistributed.
Simplicity5%Card rating 1–5 (caps, tiers, partner-only redemptions lower it).Complex cards under-deliver in practice.
Fee safety5%Lifetime free → 100; spend ≥ 120% of waiver threshold → 100; ≥ 100% → 85; else 60 × ratio; never-waived fee → 45 if net positive.Protects against spend variance: a bad month should not flip a card from “free” to “₹14,750”.

Components that do not apply (no lounge need, no lifestyle wants) are dropped and their weight is spread pro-rata over the rest, so weights always total 100%. Scores depend only on your profile – never on filters, sorting or which cards you are comparing – so the same card shows the same score everywhere.

6. Explanations

“Why it fits” lists the largest reward line, achieved milestones, fee waiver, usable lounges and matched lifestyle benefits. “Main drawback” is the single largest rupee loss: paid fee, excluded category, cap hit, missing lounge, forex cost or weak point value.

7. Data and updates

Each card record lists its official issuer page and a “last reviewed” date. Rates were reviewed on 2026-09-12. Issuers change terms frequently; treat every figure as an estimate and confirm on the issuer page before applying. See sources.

8. Limitations