Calculate cart abandonment rate from carts and checkouts
Measure how many shopping carts slip away before checkout: 1,250 carts created and 425 completed checkouts mean 825 abandoned carts and a 66% abandonment rate. Use counts from the same store and period. Free in your browser.
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Worked example
- Carts created
- 1,250
- Completed checkouts
- 425
- Abandoned carts
- 825
- Abandonment rate percent
- 66
Cart abandonment rate shows the share of created shopping carts that did not become completed checkouts. Enter the total carts created and the completed checkouts measured over the same period, and the calculator returns both the number of abandoned carts and the abandonment percentage. The calculation is deterministic and easy to audit, making it useful for recurring ecommerce reports, funnel reviews, campaign comparisons, and quick checks before publishing performance figures to a team or client.
Measure one consistent shopping period
Start with two counts drawn from the same store, definition, and reporting window. The carts created value should represent every qualifying cart opened during that period, while completed checkouts should count the carts from that population that successfully became orders. Consistency matters more than the length of the period.
A daily, weekly, monthly, or campaign-specific calculation can all be valid, but combining monthly carts with weekly checkouts produces a percentage that has no useful interpretation. Before entering the numbers, check how your analytics platform handles guest carts, repeated sessions, deleted carts, test orders, and customers who return later to buy. Those rules can differ between platforms.
Record the rule alongside recurring reports so comparisons remain meaningful when staff, tools, or tracking settings change. The calculator requires at least one created cart because a rate cannot use zero as its denominator. It also rejects completed checkouts greater than created carts, which usually signals mismatched filters, time windows, attribution rules, or source systems that need reconciliation before analysis.
Understand the abandonment formula
The calculation first subtracts completed checkouts from carts created to find abandoned carts. It then divides abandoned carts by carts created and multiplies the result by one hundred. For example, if a store records one thousand created carts and three hundred completed checkouts, seven hundred carts were abandoned and the abandonment rate is seventy percent.
This is equivalent to subtracting the checkout completion rate from one hundred percent. The output preserves the original counts, adds the abandoned-cart count, and reports the rate as a percentage rounded to no more than six decimal places for stable automated results. A checkout count equal to the cart count correctly produces zero percent abandonment.
A checkout count of zero produces one hundred percent abandonment. The formula describes funnel outcome, not customer intent: a cart may be left because of shipping cost, payment friction, comparison shopping, distraction, technical failure, or a planned later purchase. Use the rate to identify a pattern worth investigating rather than treating it as a diagnosis by itself.
Turn the percentage into a useful decision
Track the rate beside supporting dimensions such as device class, traffic source, country, product category, new versus returning customer, and checkout version. Segmenting can reveal that an acceptable overall figure hides a serious mobile payment problem or that a campaign attracts many low-intent cart creators. Compare like with like and keep sample size visible: a sharp change from ten carts is less persuasive than a modest change across thousands.
When testing a checkout improvement, define the observation window and success criterion before reviewing results, then inspect completed order value and refund quality as well as abandonment. Reducing abandonment is not valuable if a change also increases fraud, support requests, or unprofitable orders. For automation, send the two counts from a trusted reporting job and store the returned rate with the source window and filters.
Recalculate on a regular cadence, annotate releases and promotions, and investigate sustained movements instead of reacting to ordinary daily noise.
What you can do with it
Monitor the checkout funnel
Calculate a consistent daily or weekly abandonment rate and flag sustained changes for investigation.
Compare campaign traffic
Measure whether carts created by separate acquisition campaigns convert into completed checkouts at different rates.
Evaluate checkout experiments
Compare abandonment before and after a payment, shipping, or form change using matched reporting windows.
FAQ
How is cart abandonment rate calculated?
Subtract completed checkouts from carts created, divide by carts created, and multiply by one hundred.
What happens when carts created is zero?
The calculation returns an invalid input error because a percentage cannot be calculated with a zero denominator.
Can completed checkouts exceed carts created?
No. The calculator rejects that input because both counts must describe the same cart population and reporting period.
Does a high rate explain why shoppers leave?
No. It identifies the scale of abandonment, but qualitative research and segmented funnel data are needed to identify causes.
What abandonment rate do I get if every cart is checked out?
Zero percent. When completed checkouts equal carts created, no cart was abandoned. At the other end, zero completed checkouts gives one hundred percent abandonment, so the result always stays between those two limits.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/ecom/cart-abandonment-rate \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"carts_created":1250,"completed_checkouts":425}'const res = await fetch("https://api.kit.forhosting.com/ecom/cart-abandonment-rate", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"carts_created": 1250,
"completed_checkouts": 425
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/ecom/cart-abandonment-rate",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"carts_created": 1250,
"completed_checkouts": 425
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/ecom/cart-abandonment-rate", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"carts_created":1250,"completed_checkouts":425}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"carts_created":1250,"completed_checkouts":425}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/ecom/cart-abandonment-rate", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"carts_created": 1250,
"completed_checkouts": 425
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "ecom.cart_abandonment_rate",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Turn the percentage into a useful decision
The API price is $0.002 per request.
Technical questions
How much does an API calculation cost?
Each API request costs $0.002. The same deterministic formula is suitable for dashboards and scheduled reports.