Fractional weights
Fractional weights are decimal weight values that you can provide in a shipping cost rate card.
Fractional weights allow Fulfillment Optimizer to calculate more accurate shipping costs by providing a weight range. Fractional weight ranges are important in cases where a unit-of-measure or currency conversion occurred (such as converting lb to kg), or for carrier rates that are based on non-integer weights (such as 2.5 lb).
Definition of a fractional weight range
- (0.0, 0.50] shipping cost is $5.10.
- For packages that are greater than 0.0 lb and less than or equal to 0.50 lb, the rate is $5.10.
- (0.50, 1.35] shipping cost is $5.65.
- For packages that are greater than 0.50 lb and less than or equal to 1.35 lb, the rate is $5.65.
- (1.35, 2.0] shipping cost is $6.50.
- For weights that are greater than 1.35 lb and less than or equal to 2.0 lb, the rate is $6.50.
Example 1: Order weight less than 1 lb
- Item: SKU2
- Required quantity: 1
- Item weight: 0.65 lb
| CarrierService | Max weight (lb) | Rate ($) |
|---|---|---|
| UPS_Surepost | 1 | 6.27 |
| UPS_Surepost | 2 | 7.00 |
| UPS_Surepost | 3 | 7.50 |
Now, consider the rate if fractional weights are used.
| CarrierService | Min weight (lb) | Max weight (lb) | Rate ($) |
|---|---|---|---|
| UPS_Surepost | 0.0 | 0.4375 | 3.77 |
| UPS_Surepost | 0.4375 | 0.625 | 4.01 |
| UPS_Surepost | 0.625 | 0.9375 | 4.56 |
| UPS_Surepost | 0.9375 | 2.0 | 6.27 |
| UPS_Surepost | 2.0 | 3.0 | 7.50 |
Example 2: Order weight greater than 1 lb
- Item: SKU1
- Required quantity: 1
- Item weight: 1.25 lb
| CarrierService | Max weight (lb) | Rate ($) |
|---|---|---|
| USPS_Priority | 1 | 3.96 |
| USPS_Priority | 2 | 4.80 |
| UPS_Ground | 1 | 3.15 |
| UPS_Ground | 2 | 4.15 |
In this example, 1.25 lb is rounded up to 2 lb. Optimization chooses UPS_Ground at $4.15 because it is cheaper than USPS_Priority.
Now, consider the rate if fractional weights are used.
| CarrierService | Min weight (lb) | Max weight (lb) | Rate ($) |
|---|---|---|---|
| USPS_Priority | 0.0 | 1.50 | 3.96 |
| USPS_Priority | 1.50 | 2.20 | 4.80 |
| UPS_Ground | 0.0 | 1.15 | 3.15 |
| UPS_Ground | 1.15 | 1.85 | 3.70 |
| UPS_Ground | 1.85 | 2.45 | 4.15 |
In this example, 1.25 lb falls in USPS_Priority (0.0, 1.50] and UPS_Ground (1.15, 1.85] weight ranges. Optimization chooses the lower rate with UPS_Ground at $3.70. This result saves you $0.45 when compared to using integer weights.
Example 3: Rate for order weight is missing
- Item: SKU1
- Required quantity: 1
- Item weight: 1.25 lb
| CarrierService | Min weight (lb) | Max weight (lb) | Rate ($) |
|---|---|---|---|
| USPS_Priority | 0.0 | 1.50 | 3.96 |
| USPS_Priority | 1.50 | 2.20 | 4.80 |
| UPS_Ground | 0.0 | 1.1 | 3.15 |
| UPS_Ground | 1.5 | 1.85 | 3.70 |
| UPS_Ground | 1.85 | 2.45 | 4.15 |
For USPS_Priority, 1.25 lb falls in the (0.0, 1.50] range and the cost is $3.96. For UPS_Ground, 1.25 lb does not fall in any weight ranges. For UPS_Ground, the next available weight range is considered, which is (1.5, 1.85] with a cost of $3.70. Therefore, optimization chooses UPS_Ground (1.5, 1.85] at $3.70 and saves you $0.26.