Calculators
Each calculator shows its formula, units and assumptions. Nothing is estimated for you in secret.
Real discount checker
Compares an advertised discount against the lowest price you have actually seen.
advertised saving = (reference price - sale price) / reference price x 100; real saving against your own lowest seen price = (lowest seen - sale price) / lowest seen x 100
Assumptions
- The lowest price you have seen is your own observation, which this page cannot verify.
- Shipping is added to the sale price before the real saving is worked out.
A reference price set by the seller is not a market price. Where the law requires it, a reference price must be the lowest price charged in a stated earlier period.
Landed cost calculator
What a cross-border order really costs once shipping, duty and tax are added.
landed cost = (item price + shipping) + duty + tax, where duty = item price x duty rate, and tax = (item price + shipping + duty) x tax rate
Assumptions
- Duty is applied to the item price only; tax is applied to item price plus shipping plus duty. Some countries tax shipping differently, and a few apply duty to the shipping too.
- Rates are the ones you enter. This calculator does not know your country's current duty schedule or de minimis threshold.
- Currency conversion, card fees and any prepayment discount are not included.
This is arithmetic on your own figures, not a customs ruling. The carrier or customs authority decides the final amount.
Buy-now or wait planner
Weighs a likely later discount against the cost of waiting for it.
expected price if you wait = price x (1 - expected discount x probability); cost of waiting = value of use per week x weeks waited
Assumptions
- Expected discount and probability are your own estimates, and the result is only an expected value.
- Stock running out, or a price rising, is not modelled.
This arranges your own assumptions; it does not forecast prices.