Skip to content
AREM Labs

EN TR

Calculators

Calculate e-commerce profit margins, marketplace fees, and discounts.

Popular conversions

All file formats → From the blog →

What you should know

E-commerce margins erode rapidly when dimensional shipping weight exceeds actual physical weight, sales tax or VAT is calculated incorrectly, or ad spend efficiency fails to cover underlying costs. Freight couriers charge by whichever metric is higher—actual mass or volumetric size calculated from cubic dimensions—using division factors like 3000, 4000, or 5000 depending on the carrier contract. In parallel, confusing gross revenue with net profit margin often leads store managers to overlook marketplace seller fees, processing charges, and ad spend return targets, turning high-volume retail listings into unexpected cash deficits.

This suite of merchant calculators provides immediate figures for dimensional freight weights, two-way VAT calculations, return on ad spend targets, and net margin baselines. Every mathematical operation executes entirely inside your web browser via local JavaScript, ensuring sensitive sales figures, wholesale costs, and retail prices remain strictly on your device without server transmission. While these utilities deliver exact numbers for standalone unit economics and linear fee structures, they calculate discrete values rather than dynamic warehouse bin-packing algorithms, carrier accessorial fuel surcharges, or multi-bracket corporate income tax schedules.

Frequently asked questions

How is volumetric shipping weight calculated?

You multiply package length, width, and height in centimeters and divide the resulting volume by the carrier divisor, typically 3000 for standard domestic courier services or 5000 for international express air freight. Couriers compare this dimensional figure against the physical scale weight and bill you for whichever number is larger.

What is the mathematical difference between profit margin and markup?

Markup measures profit as a percentage of your wholesale cost, whereas profit margin measures profit as a percentage of your final retail selling price. For instance, buying an item for 100 dollars and selling it for 150 dollars results in a 50 percent markup but a 33.3 percent profit margin.

How do you extract net revenue from a tax-inclusive or VAT-inclusive retail price?

Divide the total gross price by one plus the tax rate expressed as a decimal, such as dividing by 1.20 for a 20 percent VAT rate. Subtracting this calculated net base amount from the total customer-facing price gives you the exact tax portion owed to authorities.