Basket Split Optimiser

Compare single-store checkout versus multi-store basket splits using item-level prices, delivery charges, and free-shipping thresholds. See best-value and simplest strategies with transparent cost breakdowns before placing an order.

⏱️ 4-7 minutes • 💪 Short

Updated 2026-04-15

How This Tool Works

📋 Purpose

Help you minimise weekly grocery spend while keeping order complexity manageable. The average UK household spends \u00a367.30 per week on groceries \u2014 even small percentage savings add up over a year.

⚙️ How It Works

  1. 1
    Add your basket items and quantities
  2. 2
    Quick-add UK supermarkets or enter retailer details manually
  3. 3
    Enter per-item prices at each store
  4. 4
    Review cheapest and simplest strategy outcomes
£67
Avg UK weekly shop
62%
Use 2+ stores
£3.85
Avg delivery fee
13.2%
Online grocery share

Shopping Basket

Your basket is empty. Add items to get started.

Retailer Setup

No retailers added yet. Pick a UK supermarket above or add one manually.

Results

Ready to Optimise

Add items to your basket and set up at least one retailer with prices to see the cheapest way to split your shop.

Shopping Split Tips

delivery
Compare delivery passes, not just fees

If you order weekly, a Tesco Delivery Saver (from £3.99/month) or Ocado Smart Pass (from £4.99/month) can be cheaper than paying per-delivery fees — factor this into your split decision.

threshold
Hit free-delivery thresholds strategically

Many UK supermarkets offer free delivery above £25–£60. If one retailer is cheaper per item but you'd fall below their free-delivery threshold, the delivery fee may wipe out your item savings.

strategy
Use Aldi and Lidl for in-store staples

Aldi and Lidl are typically 10–15% cheaper on comparable items. A split strategy might mean buying staples in-store at a discounter and ordering branded items online from Tesco or Sainsbury's.

delivery
Check for click-and-collect to avoid delivery fees

Many UK supermarkets offer free click-and-collect with a lower minimum spend. Splitting one order for delivery and one for collection can remove one delivery fee entirely.

quality
Watch out for substitution risk in split baskets

Splitting across stores means each order is smaller, which increases the chance of item substitutions. Group items where exact brand matters at one reliable retailer.

pricing
Compare unit prices, not just shelf prices

A different pack size at another store may look cheaper but cost more per kilogram. Always check the unit price (price per litre, per 100g, etc.) before entering prices.

delivery
Time your split orders for cheaper delivery slots

Midweek and off-peak delivery slots are often £1–£3 cheaper. If you're splitting anyway, use the cheaper slot window for each retailer.

strategy
Don't split for tiny savings

Managing two deliveries takes extra time and effort. If the split saves less than £3–£5, a single-store order is usually more practical for the average household.

UK Supermarket Market Share (2025)

Tesco
27.1%
Sainsbury's
15%
Asda
13.8%
Aldi
10.2%
Morrisons
8.7%
Lidl
7.9%
Waitrose
4.5%
Other
12.8%

Source: Kantar Worldpanel UK grocery market share data 2025

Data Sources & Methodology

Your Data (you enter everything)

  • Item prices — you enter the price each retailer charges for each item in your basket.
  • Delivery fees & thresholds — you set each store's delivery charge and the minimum order for free delivery.
  • Quantities — you control how many of each item you need.

Reference Data (context and defaults)

  • ONS Family Spending Survey 2023/24 — average UK weekly grocery spend for context.
  • Kantar Worldpanel 2025 — UK supermarket market share data.
  • Retailer websites (April 2026) — default delivery fees and free-delivery thresholds for major UK supermarkets.
  • IGD ShopperVista — data on UK shoppers using multiple stores.

How the optimiser works

  • All results are exact calculations from the prices you enter — nothing is estimated or averaged.
  • The tool tests every possible way to split your basket across the retailers you've configured.
  • Delivery fees are added when your order at a retailer falls below their free-delivery threshold.
  • The top 3 strategies by total cost are shown, labelled as "Best Value" and "Simplest" where relevant.

Reference data version: 2026-04. Last reviewed: April 2026. All prices in GBP.

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How the Basket Split Optimiser Works — Complete Guide

Use item-level prices, delivery fees, and free-shipping thresholds to compare single-store checkout against split-basket strategies and save on your weekly UK grocery shop.

📅 Last updated: 2026-04-15

Quick Tips

Jump-start your understanding with these essential tips

Add all recurring essentials first so delivery thresholds are evaluated against realistic order size, not a partial test basket.

Set each retailer’s delivery fee and free-shipping threshold accurately; these are often the biggest drivers of final split strategy cost.

If the cheapest result requires too many separate orders, compare with the simplest saving option to balance time, effort, and total spend.

Select from 10 UK supermarkets with pre-filled delivery fees and thresholds sourced from retailer websites to save setup time.

Step-by-Step Guide

Follow these steps to get the most from this tool

Add every item you plan to buy with accurate quantities. The optimiser tests every possible way to split these items across your chosen retailers, so a complete basket gives the most realistic results.

💡 Pro Tips:

  • Use realistic quantities from your next planned shop.
  • Include both store-cupboard staples and fresh items for a fair comparison.

Use the “Quick-add a UK supermarket” dropdown to select stores with pre-filled delivery fees and thresholds. Or add any retailer manually. Then enter each item’s price at each store using the accordion panels.

💡 Pro Tips:

  • Check prices on supermarket websites or apps for accuracy.
  • Leave an item price blank if that store does not stock it — the tool will never claim it costs £0.

Click “Optimise Basket”. The tool evaluates up to 10,000 split combinations, ranks them by total cost (items + delivery), and shows your top 3 strategies alongside the cheapest single-store baseline.

💡 Pro Tips:

  • The baseline is the cheapest valid single-store option for comparison.
  • Strategies are capped at 10,000 combinations to keep the page responsive.

Review the strategy cards or switch to comparison view for a side-by-side breakdown. Use CSV export to save the results for reference. Choose whichever strategy balances savings against order complexity best for you.

💡 Pro Tips:

  • The “Best Value” badge marks the cheapest option overall.
  • The “Simplest” badge marks the cheapest option using fewest separate orders.

Advanced Topics

Deep dives for advanced users

Small per-item savings can disappear once extra delivery fees are added. If a split strategy saves only marginally more than a single-store option, prefer the simpler route unless the savings are consistent across repeat shops. With average UK delivery fees around £3.85, you need at least that much in item-level savings per extra store to break even.

If you use click-and-collect (free at most supermarkets), set the delivery fee to £0 for those stores. This often makes split baskets dramatically more attractive because there is no extra delivery cost per retailer — only item-price differences matter.

Enter post-voucher prices where applicable. If Tesco Clubcard Prices reduces a product by 30%, enter the Clubcard price for that item. The optimiser will then factor in the real price you pay, giving a more honest comparison than shelf-price alone.

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Frequently Asked Questions

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