The "Free Shipping" Trap
Free Shipping Calculator — Is the Filler Worth It?
What this calculator does
Free shipping thresholds trick you into buying more. This calculator shows whether paying shipping is actually cheaper than reaching the threshold.
The math, with a worked example
Gap to free shipping = threshold − cart total. Filler scenario cost = cart + filler. Pay-shipping scenario cost = cart + shipping cost. A $45 cart with a $50 threshold and $6.99 shipping costs $51.99 if you pay shipping. A $5 filler makes it $50, but you are still spending $5 you did not plan to spend.
Why this matters
The free-shipping threshold is a sales tool that converts a $6.99 fee into $5+ of extra merchandise. The comparison is 3-way: pay shipping, add a filler you'd genuinely use, or walk — and the cheapest option is whichever total is lowest, not whichever avoids the fee.
Methodology and transparency
Pay-shipping total = cart + shipping; filler total = cart + filler price. The psychology is the real subject: a filler only 'wins' if it's something you'd have bought anyway — a $5 filler you didn't want is $5 spent to save $2. Everything runs in your browser; no data is sent or stored.
Last reviewed: 2026-08-08
Common questions
Is free shipping always better?
No. If the filler item costs more than shipping, you are paying extra for the illusion of free shipping.
What should I compare?
Compare the total cost of paying shipping with the total cost of adding a filler item.
Does this include taxes?
No. Add tax on your own if your state taxes shipping or filler purchases.