How Anchoring Influences UX (and Your Users' Decisions)

How Anchoring Influences UX: The Power of First Numbers

I’d like to try a quick experiment. Grab a pen and paper. Write down your current age. Would you pay that much, in dollars, for this bottle of wine? If not, how much do you think this wine is worth – without doing any research? Write that number down too.

Obviously, your age is a completely irrelevant number to how much this bottle of wine is worth. You might be anywhere between 18 and 100 years old. But I’ll bet none of you guessed that the price of this wine is $1,000 on a good day. Any of your ages would have been a bargain.

The Social Security Number Experiment

Dan Ariely and his colleagues did a similar experiment. Instead of ages, they used the last two digits of people’s Social Security Numbers. They showed different items (Bluetooth keyboards, bottles of wine, other products) and asked participants: would you pay that number – those two digits – in dollars for this item?

Here’s what happened for a Bluetooth keyboard. The bids for the exact same keyboard ranged across a $40 span. All influenced by that initial, completely arbitrary number.

This is anchoring.

Why This Matters for UX

Anchoring is one of many shortcuts we take as humans. While it could lead to incorrect estimates, the more mindful we are about it, the better our design choices will be.

Use anchoring ethically to help users make decisions – not to trick them.

Download our ‘Cognitive Biases in UX’ Cheat Sheet – 10 mental shortcuts (including anchoring) with examples and design fixes.

Every number in your interface is negotiating with every other number. The first one the user sees usually wins. That’s anchoring, and it’s one of the most reliable effects in all of behavioral science — which means your product is using it right now, whether you designed it or not.

What is anchoring, exactly?

In Tversky and Kahneman’s original experiments, people who saw a random wheel land on a high number gave systematically higher estimates of unrelated quantities — like the percentage of African nations in the UN. A number they knew was random still pulled their judgment toward it.

That’s the unsettling part: anchors work even when they’re obviously arbitrary. Your users aren’t weak-minded; they’re human. Estimation and judgment start from whatever reference point is available, and interfaces hand out reference points constantly.

Two Ways to Use Anchoring in UX Design

1. Offer a Good Default Value

Bad example:

“Your total is $25.99. Would you like to donate money to save the animals?”
“Ehh… No thanks.”

What went wrong? No good default!

Better example:

“Your total is $25.95. Would you like to round up by 5 cents to save the animals?”
“Sure, why not.”

Setting a good default removes uncertainty and establishes expectations. The donation went from high‑stakes to low‑stakes.

2. Show the Original Price

Just saying an item costs $100 gives the buyer an anchor of… $100. But if you tell the buyer the **original price was $500**, this anchors them with a much higher perceived value – making $100 feel like a bargain.

Where does anchoring show up in products?

Pricing pages. The order of your tiers is a decision about anchors. Show the enterprise plan first and the mid-tier looks reasonable. Show the cheapest first and the mid-tier looks extravagant. Neither changes the prices — only the comparison.

• Discounts. The strikethrough price exists to be an anchor, not information. “SAR 499 SAR 899” works because 899 reframes 499. This is why fake inflated “original” prices are so tempting — and why they’re both unethical and, in many markets including Saudi Arabia’s e-commerce regulations, legally risky.

• Defaults. A donation form defaulting to 100, a quantity field preset to 3, a tip screen preset to 15% — every default is an anchor that drags the final number toward it. Defaults are the most powerful anchors in your product because they arrive with your endorsement attached.

• First impressions of content. The first salary range a job seeker sees anchors every offer afterward. The first review rating colors all the rest. Sequence is persuasion.

How do you use anchoring without manipulating users?

The line is simpler than it looks: does the anchor help the user make the decision they’d want to make with full information?

• Legitimate: leading your pricing page with the plan that genuinely fits most customers, so comparisons start from realistic value.

• Legitimate: a default quantity that matches what most users actually buy.

• Manipulation: a strikethrough price that was never real.

• Manipulation: pre-checked add-ons that anchor the checkout total upward.

Users eventually discover the second category. When they do, the trust cost exceeds any conversion gain — and in review-driven markets, they tell others.

How do you audit your own anchors?

Walk your three most important flows and write down, for each screen: what is the first number or option the user sees here, and what judgment is it shaping? You’ll find anchors you didn’t intend — a placeholder example in a form field anchoring real answers, a search sort order anchoring price expectations, an onboarding step count anchoring effort expectations. Unintended anchors work exactly as hard as intended ones. They just don’t work for you.

Behavioral design done honestly is a conversion lever and a trust builder at the same time. If you want your key flows reviewed for exactly these effects, that’s part of every UX audit we run.