Trip Calculator

Trip Cost Calculator

"Should I pay cash or use points?" answered with math.

Compares the true cost of booking with cash versus each available points currency, accounting for transfer ratios, taxes/fees, and the opportunity cost of burning your points.

No API key needed. Uses local JSON data files plus flight/hotel search results.

Data Files

When to Use

• User has both cash prices (from Duffel/Ignav/Google Flights) and award prices (from seats.aero)
• User asks "should I pay cash or use points?"
• User wants to know the CPP of a specific redemption
• User is deciding between multiple booking strategies for a trip

Core Concepts

Cents Per Point (CPP)

The value you're getting per point when redeeming:

cpp = (cash_price - taxes_on_award) / points_needed × 100

A CPP above the floor valuation from points-valuations.json means you're getting above-average value. Below floor = poor redemption.

Opportunity Cost

Points have value even when unspent. Burning 100K Chase UR at 1.7 cpp (floor) means you're "spending" $1,700 in future travel flexibility:

opportunity_cost = points_needed × floor_cpp / 100

If the cash price is lower than the opportunity cost, pay cash. If higher, use points.

The Decision Framework

IF cash_price < opportunity_cost → PAY CASH (points are worth more saved)
IF cash_price > opportunity_cost → USE POINTS (good redemption)
IF cash_price ≈ opportunity_cost → PAY CASH (preserve flexibility)

The tie goes to cash because points maintain optionality.

Workflow

Step 1: Gather Prices

Cash prices (use one or more sources):

Duffel API → exact bookable fares
Ignav API → fast comparison prices
Google Flights → browser-based, includes Southwest

Award prices (use seats.aero):

Seats.aero API → cached availability across 25+ programs
Seats.aero web → live search (local Patchright only)

Step 2: Calculate CPP for Each Award Option

For each award option with a corresponding cash price:

cpp = (cash_price_usd - award_taxes_usd) / award_miles × 100

Award taxes come from seats.aero trip details (TotalTaxes field, in cents) or estimate $5.60 per segment for domestic US, $50-$200 for international (varies wildly by carrier and routing).

Step 3: Factor in Transfer Ratios

If using transferable points (Chase UR, Amex MR, etc.), the effective points cost changes:

effective_points = award_miles / transfer_ratio
effective_cpp = (cash_price - award_taxes) / effective_points × 100

Example: Flying Blue award at 50,000 miles via Capital One (1:1):

• Effective points: 50,000
• Cash price: $1,200, taxes: $100
• CPP: ($1,200 - $100) / 50,000 × 100 = 2.2 cpp

Contrast: a separate Emirates award at 72,500 Skywards miles via Capital One (4:3 ratio, the worst Cap One transfer rate):

• Effective points needed: 72,500 / 0.75 = 96,667 Cap One miles
• Same $1,200 cash equivalent: ($1,200 - $100) / 96,667 × 100 = 1.14 cpp. Worse than the Flying Blue path.

Important: pick the best currency for the destination program. Emirates Skywards has a 1:1 transfer from Bilt Rewards (no fee, instant). For the same Emirates redemption, 72,500 Bilt = 72,500 Skywards = ($1,200 - $100) / 72,500 × 100 = 1.52 cpp. Always check data/transfer-partners.json for every transferable currency the user holds before recommending a transfer — Bilt's 1:1 to Emirates beats Capital One's 4:3 by a wide margin. The skill enforces this in Step 0 (load transfer-partners first to enumerate every viable path).

Step 4: Compare Against Valuations

Load valuations from points-valuations.json:

jq -r '.credit_card_points.chase_ultimate_rewards | "Chase UR: floor \(.floor)cpp, ceiling \(.ceiling)cpp"' data/points-valuations.json

Step 5: Present Comparison

Always use markdown tables.

Flight: SFO → NRT Business Class, Aug 15

Recommendation:

• Best value: Virgin Atlantic at 7.62 cpp, but $200 in taxes and must call to book.
• Best convenience: Aeroplan at 5.44 cpp, bookable online, low taxes.
• Cash price ($4,200) vs opportunity cost ($893-$1,496): Points win decisively. Use points.

Step 6: Round-Trip and Multi-Segment

For round trips, calculate each direction separately. Award pricing is usually one-way, cash pricing is often round-trip. Make sure you're comparing apples to apples:

If cash = round-trip $4,200:
  Compare against: outbound award + return award
  e.g., 75K out + 75K return = 150K total vs $4,200 cash
  CPP = ($4,200 - $240 taxes) / 150,000 = 2.64 cpp