• Online Stores · OpenCart

Delivery calculation in the cart: the amount the buyer sees before confirming, not after

The delivery cost is the last surprise that derails a decision already made. The buyer has filled the cart, reached the end and learned that delivery costs as much as the order. Or never learned it at all, because the store says “according to the carrier's rates.” We make the amount calculate in the cart from real parameters (weight, dimensions and the chosen branch) so the buyer sees it before pressing “confirm.”

See how it works
Price
after a free audit
Guarantee
30 days after project sign-off
Focus
online stores, mostly OpenCart
Price
after a free audit
Guarantee
30
days after project sign-off
Focus
online stores, mostly OpenCart
Timeline
9
to 23 working days
Start
a free cart review
Warranty
30
days from the date the acceptance act is signed
Reply
within 2 hours
Terms
under a written contract
What's included

Complete list of work and what you get as a result

  • the delivery cost calculated in the cart before the order is confirmed
  • calculation by the actual weight and dimensions of the order, not a flat amount
  • branch selection with a search by city, not a long unfiltered list
  • a cost comparison between carriers, if there are several
  • separate rules for oversized and heavy shipments
  • accounting for the cash-on-delivery fee if it is passed on to the buyer
  • clear behavior when the carrier does not respond: an approximate amount instead of an error
  • testing each “carrier × delivery method” pair separately
  • handover with a description of how to change the rules and surcharges
When this service isn't right

What's not included — so there are no surprises at delivery

  • negotiating rates with the carrier and your contract with them
  • filling in product weights and dimensions in the catalog if they are missing
  • the delivery service's work after dispatch
  • promises of conversion growth
  • responsibility for carriers changing their rates
Who it's for

Situations where this service delivers results

Scenario 1 of 4

A store with products of different weights

When one catalog holds both a 200-gram trinket and 20-kilogram appliances, a flat delivery fee either scares the buyer off or eats into your margin.

We'll review your situation in a free audit
A free review of your cart

We check whether an exact calculation is possible for you at all: it depends not on code but on product data.

What we measure

  1. Whether product cards have weightsWithout them, delivery cannot be calculated. This is the most common obstacle, and it usually surfaces in the middle of the work, so we look at it first.
  2. Whether there are dimensionsFor a light but bulky item, the carrier charges by volumetric weight. Without dimensions, such shipments will always be calculated incorrectly.
  3. How many carriers and methodsEach pair is a separate scenario with its own rules and zones. This is the main factor in the scope of work.
  4. What the buyer sees now“According to the carrier's rates,” a flat amount or nothing. This determines how noticeable the change will be.
  5. Whether you add surchargesPackaging, insurance, the cash-on-delivery fee: all of this has to be accounted for, otherwise the calculation will diverge from the actual amount.
  6. What to do with oversized itemsItems that do not fit the standard rates need a separate rule or approval from a manager.

What you get

  • an answer on whether an exact calculation is possible on your data
  • a list of what the catalog is missing for it
  • an estimate of the work broken down by stage
  • an honest answer if it is simpler to keep a flat amount for now

Timeline: 2–4 working days

Why is it free

Delivery calculation depends on product data, not code. Until you have looked at the catalog, any estimate would be guesswork.

What's next

You get a list and an estimate. Then you decide for yourself, and the document stays with you.

Short form: your contact and site URL
Contract and paperwork

We work officially

Contract, act and invoice — for every project, not just large ones.

Trusted by6 brands

Trusted by: Kvant Energy, GYPSUN, Naturel Cosmetics, Pancer Protection, LUGI, BeeTech

Terms fixed in writing8 points

  • Contract, act and 30-day warranty

    Every project gets a written contract: scope, deadlines, amount, acceptance procedure. After delivery — act and invoice, then 30 calendar days of warranty.

  • Sole proprietor & bank transfer

    The contractor is a registered sole proprietor. Payment by invoice with closing documents.

  • Rights & access — yours

    Code, design and materials transfer to you after full payment. Domain, hosting, repository and analytics are registered to you.

  • Client portal instead of email chains

    During the project you get access to a portal: contracts, invoices, acts and project status in one place.

  • Sites in nine countries

    Our sites run in nine countries: besides Ukraine — Poland, Germany, Austria, England, Norway, Bulgaria, Moldova and Spain.

  • Verifiable numbers

    Every case in the portfolio comes with a link to a live site and a technical measurement.

  • Audit first, then pricing

    There is no price list on the site intentionally: the scope of the same work differs multiples between clients.

  • We say "no" when unsure

    If the task isn't ours or the deadline is unrealistic — we tell you upfront.

  • Contract, act and 30-day warranty

    Every project gets a written contract: scope, deadlines, amount, acceptance procedure. After delivery — act and invoice, then 30 calendar days of warranty.

  • Sole proprietor & bank transfer

    The contractor is a registered sole proprietor. Payment by invoice with closing documents.

  • Rights & access — yours

    Code, design and materials transfer to you after full payment. Domain, hosting, repository and analytics are registered to you.

  • Client portal instead of email chains

    During the project you get access to a portal: contracts, invoices, acts and project status in one place.

  • Sites in nine countries

    Our sites run in nine countries: besides Ukraine — Poland, Germany, Austria, England, Norway, Bulgaria, Moldova and Spain.

  • Verifiable numbers

    Every case in the portfolio comes with a link to a live site and a technical measurement.

  • Audit first, then pricing

    There is no price list on the site intentionally: the scope of the same work differs multiples between clients.

  • We say "no" when unsure

    If the task isn't ours or the deadline is unrealistic — we tell you upfront.

We sign NDAs on request. After completing the work, we delete our access to your services ourselves.

What affects the price

Why two seemingly identical tasks are priced differently

  • Number of carriersNova Poshta alone is one set of rules. Four carriers mean four different rate logics, zones and address formats.
  • State of product dataIf there are no weights and dimensions, they have to be added first. This work is on your side, and it usually determines the real timeline.
  • Calculation by volumetric weightPlain weight is easy to calculate. Volumetric weight adds dimensions, rounding rules and a check of which is greater, the actual weight or the volumetric one.
  • Surcharges and feesPackaging, insurance, the cash-on-delivery fee: each adds a line to the calculation and has to be clear to the buyer rather than a surprise.
  • Failure behaviorThe carrier sometimes does not respond. The right reaction is to show an approximate amount and warn the buyer, not to stop checkout with an error.
  • State of the cart codeIf the cart has already been rewritten on top of the standard one, we first need to understand the existing calculation logic.
Cases

Tasks and results in numbers — all metrics measured by us

an online store delivering sweets, snacks and gift sets

Task
Sell sweets, snacks and gift sets with delivery across Ukraine: a catalog with filters by type and occasion, a cart with a choice of delivery, online payment. A particular focus is the speed of the mobile version, because in this niche most orders are impulse purchases made from a phone.
Solution
A store on OpenCart 3.x (octemplates/OCT theme, HTTP/2). 5 online payment methods are connected — LiqPay, WayForPay, Privat24, Visa, Mastercard — and 4 delivery methods: Nova Poshta, Ukrposhta, pickup, courier. Free delivery to a Nova Poshta branch on orders from UAH 2,500 is implemented (a banner on the home page), along with contact via Telegram, Viber, WhatsApp, Instagram and Facebook.
Result
As of 31 July 2026 the store is up (HTTP 200, HTTPS): first server response 403 ms, full HTML load 532 ms; LiqPay, WayForPay and Privat24 online payment and Visa/Mastercard cards are connected, plus 4 delivery methods; the home page runs a free Nova Poshta delivery offer on orders from UAH 2,500.

Kvant Energy

a retail online store of heating equipment, a catalog of ~3,500 SKUs

Task
Bring the full range of heating equipment online (bimetallic radiators, electric radiators, breezers, fan heaters, underfloor heating, thermostats), with navigation and filters built for comparing technical specifications, and with a checkout that serves both retail buyers and sole traders (FOP) and LLCs paying VAT.
Solution
A store on OpenCart 3 (oct_showcase theme, nginx). Two language versions, uk/ru, with correct hreflang and x-default. Checkout with monobank, payment on delivery via the carrier, cash on receipt and a bank-transfer invoice for sole traders (FOP) and LLCs paying VAT. Four delivery methods: Nova Poshta, Meest Express, Delivery Auto, pickup in Kharkiv. GTM/GA4, Google Maps and the Telegram/Viber/WhatsApp messengers are connected.
Result
3,565 product cards in the live catalog (measured on 31 July 2026 with OpenCart's built-in search and an empty query: 36 pages of 100 items, the last one with 65). TTFB 0.52 s, full HTML load 0.66 s at 296 KB of markup. 4 payment methods and 4 delivery methods at checkout. Two language versions with valid hreflang and x-default.

Did not find your case?

Describe how it works on your side — we will tell you whether “Delivery calculation in the cart” fits and what it means in your situation. No brief and no call: one question, one answer.

Process steps

Transparent stages with approval at every step

Total duration:5–20 days

  1. Data review

    2–4 working days

    We check whether the catalog has weights and dimensions and how reliable they are. This determines whether an exact calculation is possible at all.

  2. Agreeing on the rules

    1–3 working days

    We agree on carriers, zones, surcharges and what to do with oversized items. We record who pays the cash-on-delivery fee.

  3. Connecting carriers

    3–8 working days

    We connect the rates and branch directories and build a branch search by city. We work in a test environment.

  4. Calculation and rules

    2–6 working days

    We implement calculation by weight and dimensions, surcharges, separate rules for oversized items and the behavior when a branch is unavailable.

  5. Failures and testing

    2–4 working days

    We set up the response to carrier silence and go through every “carrier × method” pair and the edge cases: very heavy, very small, oversized.

  6. Release and reconciliation

    1–2 working days

    We roll out the changes and compare the calculation with the actual amounts on the first orders. Then the 30-day warranty from the date the acceptance act is signed applies.

Technologies & integrations

What we build on and what it connects to

Stack

  • OpenCart
  • WooCommerce
  • PHP
  • JavaScript
  • MySQL
  • Next.js
  • Git

Integrations

  • Nova Poshta
  • Ukrposhta
  • Meest Express
  • Delivery Auto
  • Google Analytics 4
  • Google Tag Manager
Calculation by weight or a flat delivery fee

How this option differs from the alternative

A flat amount for all ordersOur approach
Small ordersoverpay and get canceled more oftencost little, as they should
Heavy ordersyou pay the differenceare charged fairly, the margin is preserved
Buyer trustdoes not understand where the figure came fromsees what they are paying for
Data requirementsnothing neededweights and dimensions are needed in the catalog
Complexityminimal, and enough for products of uniform weighthigher, but the amount matches the actual cost
What we need from you

We can't start without this — best to prepare in advance

  1. a list of the carriers and delivery methods to support
  2. whether product cards have weights and dimensions
  3. rules for oversized and heavy shipments, if you have them
  4. whether you add anything to the carrier's rate: packaging, insurance
  5. who pays the cash-on-delivery fee
  6. who on your side accepts the work
If something is missing — let us know, we'll help you gather it or do it as a separate task.
FAQ

Most frequently asked questions — with concrete answers

We do not have product weights. Can delivery still be calculated?

Not accurately, no. This is the most common obstacle in this task, and it usually surfaces in the middle of the work, when redoing things is expensive. That is why during the review we look at the catalog first: if there are no weights, they have to be added first, and that work is on your side. You can start with the best-selling categories rather than the whole catalog at once.

What is volumetric weight and why do dimensions matter?

The carrier charges by the greater of two values: the actual weight and the volumetric weight calculated from the dimensions. A light but large box costs as much as a heavy one. Without dimensions, such shipments will always be calculated cheaper than they really are, and you will pay the difference.

What happens if the carrier does not respond?

Checkout must not stop. The right behavior is to show an approximate amount with an honest note, “the final cost will be confirmed,” and let the buyer complete the order. An error at this step means a lost order, even though the problem is temporary and not yours.

Can we show the cost from several carriers at once?

Yes, and it is often useful: the buyer chooses between cheaper and faster. But each added carrier is a separate set of rules and zones, so it is worth starting with the ones you actually use rather than connecting everything in sight.

Who pays the cash-on-delivery fee?

That is your decision, and it has to be made before implementation. If the buyer pays the fee, it must be visible in the cart rather than showing up at the branch. Otherwise it is the same surprise we are removing, just in a different place.

How long does it take?

9 to 23 working days. Connecting the rates is quick; the time goes into rules for oversized items, surcharges and testing edge cases. If the catalog lacks weights, the real timeline depends on how quickly you add them.

Will the calculation match the actual amount?

On typical shipments, yes, provided the product data is accurate. Discrepancies appear where the weight in the catalog differs from the real one or where packaging adds volume. That is why after launch we reconcile the calculation with the actual amounts on the first orders and adjust the surcharges.

Will this increase the number of orders?

We do not promise figures. What definitely goes away is the surprise at the last step that makes some buyers leave. How noticeable this is in your sales depends on how many of them dropped off at exactly that point, and we set up analytics events so you can see it for yourself.

Demo

Your catalogue on a phone screen

This is how your store can look on a phone: a collection banner, popular products and a cart one tap away. Tap “Add to cart” and the counter in the header updates, just like in a real store.

  • Collection bannerThe first screen shows what is new, not a logo.
  • Product cardsPhoto, price and a button — no extra page to open.
  • One-tap cartThe counter in the header updates instantly, like in a real store.
Stores in the portfolio
This is a demo interface, not a client's store. Live projects are in the portfolio.
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Let's check whether an exact calculation is possible

We will look at your catalog and tell you what is missing to calculate delivery. The review is free, and we reply within 2 hours.

View cases
  • Reply within 2 hours
  • No commitment
  • We work under a contract

There is no price list on the site on purpose: the same work differs several times over between two clients, and a “from” figure explains nothing in that case. First a free audit — we count your pages, duplicates and speed — then we name the sum and the deadline and fix both in the contract.