The actual selected base
One 21.95 Wild Honey set,one 21.95 Nice On Ice set and one 26.95 Nostalgic Christmas set total 70.85 USD. The tool stores that as 7085 cents. A confirmed 70.85 merchandise credit is allowed and leaves zero merchandise. A 70.86 credit is one cent too high and is rejected rather than silently clamped.
Keep charge lines separate
If your actual shipping is 4.99,tax 1.25 and other charges 0,the entered total after full merchandise credit is 6.24. Those are user-entered example charges,not a live tax or shipping quote. A promotion may have specific treatment;use the actual checkout lines rather than assume free merchandise removes every charge.
Unknown is not zero
Blank shipping,tax or other charges withhold the full total. Enter 0 only when confirmed. Negative,exponent,over-precision and over-limit amounts are unresolved. A merchandise subtotal can be known while the final order total remains unknown. The calculator never requests a payment card or address.
Decimal boundaries matter
An edited 0.10 price at quantity 3 creates 0.30 merchandise. Exact 0.30 credit is valid and 0.31 is not. Likewise 47.99 times 2 is 95.98. Integer cents avoid binary floating-point residue at full-credit boundaries. Edited inputs are your quotes,not newly observed retailer prices.
Do not double-count a discount
If checkout already reduces a unit price,do not add the same promotion again as a credit unless the receipt actually has both adjustments. A page saying discount applied in cart does not establish a percentage or eligibility by itself. The budget tool calculates inputs;it does not apply coupons,reserve stock or submit an order.
Sources & scope
Checked November 5, 2026. Manufacturer and retailer references support the specific statements. Dated displayed prices are not final checkout quotes, performance rankings or performance testing. This shopping reference does not replace the exact product label or qualified individual advice. Current received labels and independent textile/sleepwear-safety/content/commerce review remain pending.