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Amazon FBA vs FBM Calculator

Which fulfillment method is more profitable? Enter product weight, dimensions, and volume to see size tier, fees, and annual profit difference.

Where this fits

This tool lives inside Seller OS and is most useful for sellers and founders.

Corp Tax Rate21%
SE Threshold$400
FICA Cap 2024$168,600

Product Details

Dimensions & Weight

Size Tier

Small Oversize

Sports equipment, furniture under 70 lbs

FBA vs FBM: Per Unit Profit

FBA

$13.51

Referral + fulfillment fees

FBM

$23.00

You handle shipping

Annual Difference

$1,138.80

FBM (Self-Ship) wins

Recommended
FBM (Self-Ship)
FBA Fee/Unit
$14.49
FBM Shipping
$5.00
Difference/Unit
$9.49
Seller playbook · Fulfillment decision

Self-ship is currently protecting more profit than FBA.

FBM (Self-Ship) is ahead with a Small Oversize item at $40.00 sale price and $12.00 COGS. The current fulfillment choice changes profit by $9.49 per unit, so this is not an operational detail — it is a core margin decision.

What To Do Next

Stick with FBM until you can improve sourcing, reduce dimensions, or raise price enough to absorb FBA fees.

The winner is ahead by $9.49 per unit, which compounds to $1,138.80 a year at 10 units a month.

Run the full Amazon profitability model next if you need to pressure-test PPC, returns, and storage before scaling.

Winning path

FBM (Self-Ship)

Small Oversize size tier

Difference per unit

$9.49

FBM (Self-Ship) advantage per sale

Annual gap

$1,138.80

10 units per month

FBA fee burden

$14.49

Referral plus fulfillment per unit

1

Determine size tier

Weight + dimensions (L×W×H)

2 lbs, 10"×8"×4"

= Small Oversize

Amazon FBA has 5 size tiers with different fulfillment fees. Your product fits Small Oversize tier. Example: Sports equipment, furniture under 70 lbs

Amazon FBA size tier pricing

2

FBA referral fee (15%)

sale price × 0.15

$40.00 × 0.15 = $6.00

= $6.00

Amazon charges 15% referral fee on most product categories.

Amazon seller central

3

FBA fulfillment fee

Size tier fee (Small Oversize)

$8.49 per unit

= $8.49

Covers picking, packing, shipping, and customer service. Varies by size tier.

Amazon FBA fulfillment pricing

4

FBA total fees per unit

referral fee + fulfillment fee

$6.00 + $8.49 = $14.49

= $14.49

Combined cost to sell through FBA per unit.

FBA fee calculation

5

FBA net profit per unit

sale price − FBA fees − COGS

$40.00 − $14.49 − $12.00 = $13.51

= $13.51

Your profit per unit after all Amazon fees and your cost.

Profit calculation

6

FBM shipping estimate

flat estimated shipping cost per unit

$5.00 per unit

= $5.00

This tool uses a mid-range domestic self-ship estimate for FBM to compare against Amazon's FBA handling costs.

FBM shipping assumption used by the calculator

7

FBM net profit per unit

sale price − FBM shipping estimate − COGS

$40.00 − $5.00 − $12.00 = $23.00

= $23.00

FBM skips Amazon fulfillment fees, but you absorb the shipping cost and operational work yourself.

FBM unit profit formula

8

Per-unit profit difference

FBM net profit per unit − FBA net profit per unit

$23.00 − $13.51 = $9.49

= $9.49

This isolates the fulfillment-model effect before monthly volume is applied.

Per-unit profit comparison

9

Annual profit difference

(FBM profit − FBA profit) × units per month × 12

($23.00 − $13.51) × 10 × 12 = $1,138.80

= $1,138.80

Over a year, FBM (Self-Ship) nets you $1,138.80 more profit.

Annual profit comparison

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