Master accurate shipping calculations so postage costs never eat into your margins.
Never Lose Money on Shipping Again Underestimating postage is one of the easiest ways to kill your profit margins. Here's how to calculate accurately every time. Step 1: Measure Your Item Dimensions matter as much as weight. Couriers charge based on both. Measure your item when packaged: Length (longest side) Width Height/depth Add 1 2cm to each measurement to account for packaging materials. Step 2: Weigh Accurately Weigh WITH packaging. The box, bubble wrap, tape, and label all count. Pro tip: Keep pre made packages of common items and note their typical weights. Add 50 100g buffer for: Address labels Extra tape Slight scale variations Step 3: Check Courier Rates Compare prices across services: Royal Mail Evri DPD Yodel Online label services often cheaper than Post Office counter prices. Step 4: Decide Who Pays Option A: Buyer pays shipping List item price + separate postage Transparent but may deter budget buyers Option B: "Free" shipping Build postage cost into item price Better conversion rates Hides true postage cost Step 5: Calculate Net Profit Formula: Sale Price Platform Fees Shipping Cost Packaging Cost Item Cost = Net Profit Example: Sale price: £25 (inc "free" shipping) Platform fees (13%): £3.25 Shipping cost: £3.50 Packaging: £0.80 Item cost: £8 Net profit: £9.45 Common Mistakes ❌ Forgetting packaging weight ❌ Using counter prices instead of online rates ❌ Not accounting for packaging materials cost ❌ Underestimating large/awkward items Pro Tip Always round up slightly on shipping estimates to cover unexpected costs. That extra 50p buffer protects your margins