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
| File | Purpose |
|---|---|
data/points-valuations.json | CPP valuations per program (floor/ceiling) |
data/transfer-partners.json | Credit card → loyalty program transfer ratios |
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:
bashjq -r '.credit_card_points.chase_ultimate_rewards | "Chase UR: floor \(.floor)cpp, ceiling \(.ceiling)cpp"' data/points-valuations.json
| Rating | CPP vs Floor | Meaning |
|---|---|---|
| Excellent | > ceiling | Exceptional redemption. Book it. |
| Good | > floor | Above average. Solid use of points. |
| Fair | 0.8× to 1× floor | Mediocre. Consider cash instead. |
| Poor | < 0.8× floor | Bad deal. Pay cash. |
Step 5: Present Comparison
Always use markdown tables.
Flight: SFO → NRT Business Class, Aug 15
| Option | Program | Miles/Points | Taxes | Cash Equiv | CPP | Rating |
|---|---|---|---|---|---|---|
| Cash | — | — | — | $4,200 | — | — |
| United via Chase UR | United | 88,000 UR | $45 | $1,496 | 4.72 | Excellent |
| Aeroplan via Chase UR | Aeroplan | 75,000 UR | $120 | $1,275 | 5.44 | Excellent |
| Alaska via Bilt | Alaska | 55,000 Bilt | $30 | $935 | 7.58 | Excellent |
| Virgin Atlantic → ANA via Chase UR | VA | 52,500 UR | $200 | $893 | 7.62 | Excellent |
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 - $240 taxes) / 150,000 = 2.64 cpp
jq Recipes
Get floor valuation for a currency
bashjq -r '.credit_card_points.chase_ultimate_rewards.floor' data/points-valuations.json
Calculate opportunity cost
bash# 75,000 Chase UR points POINTS=75000 FLOOR=$(jq -r '.credit_card_points.chase_ultimate_rewards.floor' data/points-valuations.json) echo "$POINTS points × $FLOOR cpp = \$$(echo "$POINTS * $FLOOR / 100" | bc) opportunity cost"
Full comparison for one route
bash# Cash: $4200 round trip. Award: 75000 Aeroplan each way, $120 taxes each way. CASH=4200 MILES_ONEWAY=75000 TAXES_ONEWAY=120 TOTAL_MILES=$((MILES_ONEWAY * 2)) TOTAL_TAXES=$((TAXES_ONEWAY * 2)) echo "Cash: \$$CASH" echo "Award: $TOTAL_MILES miles + \$$TOTAL_TAXES taxes" echo "CPP: $(echo "scale=2; ($CASH - $TOTAL_TAXES) / $TOTAL_MILES * 100" | bc)" # Opportunity cost at floor valuation FLOOR=$(jq -r '.credit_card_points.chase_ultimate_rewards.floor' data/points-valuations.json) echo "Opportunity cost: \$$(echo "scale=0; $TOTAL_MILES * $FLOOR / 100" | bc)"
Hotel Comparison
The same framework works for hotels:
hotel_cpp = (cash_rate_per_night × nights) / total_points × 100
Hotel redemptions vary more than flights. Use points-valuations.json hotel section:
- Hyatt: floor 1.4 cpp (consistently best hotel currency)
- Hilton: floor 0.4 cpp (high point costs, low per-point value)
- Marriott: floor 0.6 cpp
For premium hotel programs (FHR, THC, Chase Edit), factor in the additional benefits (breakfast, upgrade, credit, late checkout) when comparing cash vs points. A $500/night FHR rate with $100 breakfast credit and potential suite upgrade might be worth more than the sticker price.
Chase Travel Portal vs Transfer
Chase Sapphire Reserve uses dynamic Points Boost pricing in the Chase travel portal: roughly 1.5-2.0 cpp on select bookings, but not a guaranteed floor on every booking. The historical 1.5 cpp fixed multiplier is gone — current redemptions vary by route, date, and inventory. Always check the actual portal price before assuming a rate.
Rough decision rule, with the caveat that you must verify the actual portal quote:
If actual portal CPP > award CPP → portal wins If award CPP > actual portal CPP → transfer to partner wins
Sapphire Preferred is similar (1.5-1.75 cpp typical via Points Boost). Amex portal is ~1.0 cpp for flights (1 cent per MR point). Capital One portal is ~0.75-1.0 cpp.
Always pull the real portal quote via the chase-travel or amex-travel skills before making a points-vs-portal recommendation. Don't assume the headline rate applies to your specific booking.
Common Pitfalls
- Ignoring taxes/fees on awards. Some airlines (especially BA, Lufthansa, Singapore on own metal) add $500+ in fuel surcharges to award tickets. Always subtract taxes before calculating CPP.
- Comparing one-way award to round-trip cash. Make sure denominators match.
- Forgetting transfer ratios. 50K miles via Amex → Emirates at 5:4 costs 62,500 MR, not 50,000.
- Not checking portal pricing. Sometimes Chase/Amex portal pricing beats the transfer math.
- Over-optimizing small differences. If two options are within 0.5 cpp of each other, pick the one with better routing, lower taxes, or more flexibility.
Notes
- Point valuations are subjective. The floor from
points-valuations.jsonis the most defensible number. - "Opportunity cost" assumes you WILL use those points eventually at floor value. If you're sitting on a huge balance with no plans, the real opportunity cost is lower.
- Currency devaluation risk matters for long-term holdings. Points are depreciating assets.
- Transfer bonuses can shift the math significantly. A 30% bonus on Chase → Flying Blue means 75K UR becomes 97.5K Flying Blue miles.
