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Ecommerce Google Ads: Start at £20–£50/day with an agency checklist

Biplab Poddar
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Start with a daily budget that targets a small number of conversions per day, or a minimum range suitable for a new store testing the waters. Before you commit a penny, check that your conversion tracking is firing correctly: everything else, from campaign splits to bidding strategy, depends on that data being accurate. The sections below walk through exactly how to allocate and adjust that budget once it’s live.

TL;DR:

  • Setting a budget based on target ROAS or CPA requires reliable conversion tracking; inaccuracies can lead to overspending or underspending.
  • The average daily budget is a pacing estimate, and campaigns can spend up to twice that amount daily, with a monthly cap of 30.4 times the daily budget.
  • Most new stores should allocate around 70% of their ad spend to Shopping and Performance Max campaigns for effective product placement.
  • Using automated bidding strategies like Maximise conversion value or Target ROAS depends on having sufficient conversion history to avoid under-spending.
  • During peak seasons, budget should be increased two to three times normal levels starting two to three weeks prior, with seasonality adjustments and proper feed health checks.
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Table of Contents

Practical budget ranges and rules of thumb for ecommerce

Most new ecommerce stores do well starting with a modest daily budget that covers enough impressions and clicks to gather meaningful signal without burning cash on an unproven setup. Growing stores with validated products typically increase their daily budget accordingly, while brands in scaling mode allocate larger daily budgets across Shopping, Performance Max and Search combined. These bands are starting points, not ceilings: your actual number should come from your own numbers, not a generic benchmark.

The most reliable way to set a budget is to work backwards from your goals. If you know your target ROAS and your average order value, the maths is straightforward:

None of these calculations work if your tracking is unreliable, which is why checking it comes before setting a number, not after.

One detail that trips up a lot of advertisers: the daily budget you set is an average, not a cap. Google explains that a campaign can spend up to twice its average daily budget on any single day, and up to 30.4 times the average daily budget across a month, though your billed costs will not exceed your monthly spending limit. In practice, that means a £50 daily budget could see a £90 day during a high-traffic period, balanced out by quieter days elsewhere in the month. This is normal pacing behaviour, not an overcharge, but it’s worth understanding before you panic over a single day’s report.

Google’s own budget calculator offers a useful second opinion: the Google Ads Budget & Cost Calculator lets you model spend against estimated clicks and conversions for your sector, which is a sensible sanity check before you commit to a monthly figure.

Set your budget from your numbers, check it against the pacing rules above, and review it weekly rather than daily. Daily swings are expected; the trend over a fortnight is what tells you whether the budget is working.

How to split your Google Ads budget across campaign types

Shopping and Performance Max should carry the bulk of spend for most product-based ecommerce stores, because they put your products directly in front of shoppers who are already comparing options. A sensible starting split looks like this:

Search still earns its place, particularly for branded terms, high-intent category searches and any product where buyers do real research before purchasing. If your margins are thin on impulse items but strong on considered purchases, Search budget should lean towards the latter.

It’s the budget you use to test new Performance Max asset groups, new Shopping feed segments or a fresh Search campaign structure, without risking the core revenue campaigns that are already working. Keep this separate in reporting so a bad test doesn’t quietly drag down your main account’s numbers.

As performance data accumulates, reallocate based on conversion value per pound spent rather than clicks or impressions. A campaign type pulling in strong revenue at a sustainable ROAS deserves more budget; one that’s burning spend on clicks that don’t convert should shrink, even if it looks busy in the dashboard. For a deeper breakdown of how Shopping, Performance Max, Search and Display fit together at different store sizes, see our Google Ads campaign types for ecommerce guide. If Shopping specifically is where you’re unsure about numbers, our piece on what budget for Google Shopping actually works goes into more detail on sizing that piece of the split.

Choosing bidding strategies and how they affect budget use

Your bidding strategy determines how efficiently your budget gets spent, and picking the wrong one for your stage can quietly waste a large share of it. Google documents the major bid strategies and how to match them to campaign goals, and the differences matter more than they first appear:

Google’s own guidance is clear on sequencing: use Maximise conversion value to scale new campaigns with a limited budget rather than imposing a strict ROAS target too early, because tight constraints can stop the algorithm learning properly. Some value-based strategies also carry minimum conversion volume requirements before they’re eligible to run effectively, so check eligibility before switching a low-volume campaign onto Target ROAS.

A rough rule that holds up well in practice: don’t move to Target ROAS until a campaign has built a consistent conversion history, generally once it’s producing conversions reliably enough that the algorithm has real signal to work from. Switching too early often results in the campaign under-spending its budget because the algorithm becomes too cautious.

Pro Tip: If a campaign keeps under-delivering against its daily budget, loosen the ROAS target or switch to Maximise conversion value for two to three weeks to rebuild data before tightening again.

Manual CPC still has a place, particularly for brand defence campaigns or very narrow product categories where automated bidding doesn’t have enough volume to learn from. For most product catalogues, though, automated value-based bidding will use your budget more efficiently than manual bids once it has data to work with. Our guide to bidding strategies for ecommerce brands and the broader explainer on how to choose a bid strategy both go further into matching strategy to campaign maturity.

Conversion tracking, conversion value and ROAS: the engine behind budget efficiency

None of the budgeting formulas above work without accurate conversion values, because value-based bidding spends your money based on what it thinks each conversion is worth. Google’s conversion value guidance recommends setting transaction-specific values rather than a flat figure for every conversion, so the system can tell a £150 order apart from a £15 one and bid accordingly. If your margins vary significantly by SKU, weighting conversion values by margin rather than raw revenue can sharpen how your budget gets allocated between product lines, though this needs careful setup to avoid double-counting.

Once values are set up correctly, your conversion value to cost ratio becomes the main signal for budget decisions:

A frequent pitfall: duplicate conversion tags, missing refund adjustments or a tracking tag that fires on every page view rather than only on purchase completion. Any of these can make a budget look far less efficient than it actually is, leading advertisers to cut spend on campaigns that were working fine. Before adjusting any budget based on a dip in ROAS, rule out a tracking problem first.

Properly instrumented transaction values let Maximise conversion value and Target ROAS bidding optimise towards actual revenue rather than guesswork, which is the difference between a budget that scales profitably and one that just scales spend. For a practical walkthrough of lifting your return once tracking is solid, our guide on how to improve ROAS for ecommerce brands covers the tactical side in more depth.

Seasonality and holiday planning: how to ramp budgets and protect ROAS

Holiday periods reward preparation more than any other stretch of the year, and Google’s own guidance for Shopping and Performance Max gives a clear starting point. For peak periods, Google recommends planning a budget around 2x your normal target spend, rising to as much as 3x for the heaviest holiday weeks, to make sure the campaign isn’t capped just as demand peaks.

Here’s a sensible operational sequence to follow in the run-up:

  1. Start the ramp two to three weeks before the peak, rather than the week of, so the algorithm has time to adjust before demand spikes.
  2. Consider temporarily lowering your ROAS target during the ramp. Google notes this can help capture additional holiday demand that a strict target would otherwise block, even at a slightly lower margin per sale.
  3. Avoid major structural changes once the ramp begins. Changing budgets, targets or campaign structure mid-learning resets the algorithm’s progress at the worst possible time.
  4. Check Merchant Centre health, including disapprovals, out-of-stock flags and feed freshness, since a broken feed during peak season wastes the extra budget you just committed.
  5. Apply seasonality adjustments in Google Ads for the specific dates you expect a demand spike, so the bidding system anticipates the change rather than reacting to it after the fact.
  6. Exclude the peak period from historical data windows once it ends, so a single unusual week doesn’t skew your “normal” benchmarks for months afterwards.

Inventory planning deserves equal attention to budget planning. A bigger budget driving more traffic to an out-of-stock product is simply wasted spend, so confirm stock levels against forecasted demand before the ramp starts, not during it.

What to do with a small budget: testing, learning and scaling without wasting spend

A small budget can still produce reliable results, provided you set realistic expectations about what it can learn from. Automated bidding strategies need a steady run of conversions to optimise properly, so with a tight daily spend, your early weeks should be judged on whether conversions are happening consistently, not on hitting an aggressive ROAS target from day one.

A structure that tends to work well for limited budgets is the two-campaign approach:

This combination avoids spreading a small budget across too many campaign types, which is one of the fastest ways to starve every single one of the data it needs. Google’s guidance on matching bid strategy to budget and goals backs this focused approach for accounts without much historical volume to lean on.

When you do want to test something new, a creative variant, a new audience signal or a different landing page, ring-fence a small slice of budget for it rather than letting it compete with your proven campaigns. Give any test at least two to three weeks before judging it, since early data on a small budget is noisy by nature.

Pro Tip: Resist the urge to change a small-budget campaign daily. Weekly reviews give the algorithm enough runway to show a real trend, rather than reacting to normal day-to-day noise.

Oxedent field-tested checklist and optimisation priorities for ecommerce budgets

Turning a raw number into a profitable campaign comes down to sequencing. On day one, we check conversion tracking accuracy, Merchant Centre feed health and which SKUs actually drive margin, since budgeting around the wrong products undermines everything that follows. In week one, the priority shifts to trimming wasted spend: pausing underperforming search terms, fixing feed disapprovals and tightening audience exclusions. By month one, the focus moves to scaling what’s working, reallocating budget towards the campaign types and products proving out the best conversion value to cost ratio.

A few checks we return to on every account:

The agency typically works with ecommerce brands running meaningful monthly ad budgets, focusing on optimising their campaigns. Accounts with limited spend may benefit from focusing on foundational setup first.

Pro Tip: Run a feed health check before touching your bidding strategy. A broken feed will undermine even the best-tuned Target ROAS setup.

An agency view on common budgeting mistakes

The mistake we see most often isn’t underspending, it’s demanding a strict ROAS target before a campaign has any real conversion history to learn from. One client cut budgets the moment ROAS dipped in week two, which simply reset the learning phase and delayed the recovery they were chasing. Disciplined measurement, waiting for a stable conversion value to cost ratio before tightening targets, consistently produces better scaling decisions than reacting to short-term swings. If you’d like a second opinion on your own account, we offer a free audit to talk through where your budget is leaking.

— Biplab

How Oxedent can help: audits, PPC management and a free audit offer

Getting the budget right is only half the job: the other half is the daily discipline of reallocating spend as data comes in, which is where most in-house teams run short on time. Oxedent focuses exclusively on ecommerce paid media, which means every recommendation is built around revenue and ROAS rather than vanity metrics like clicks.

We work best with established ecommerce brands running meaningful monthly ad budgets, without locking anyone into long-term contracts. If that sounds like your business, request your free audit and we’ll show you exactly where your spend is going.

FAQ

Is $10 a day enough for Google Ads?

A $10 daily budget can work for very narrow, low-competition niches, but it rarely generates enough clicks or conversions for the automated bidding algorithms to learn effectively. Most ecommerce stores need a higher starting point, generally in the £20 to £50 per day range, to gather reliable signal within a reasonable timeframe.

Is $20 a day good for Google Ads?

$20 a day is a reasonable entry point for a new ecommerce store testing a focused Shopping feed alongside a small, high-intent Search campaign. It won’t support broad targeting across many campaign types at once, so keeping the structure tight matters more than the budget size itself.

How much does 1,000 impressions cost in Google Ads?

Cost per impression varies by industry, competition and bidding strategy, and Google does not publish a single fixed rate for this. The most reliable way to estimate it for your own sector is through the Google Ads Budget & Cost Calculator, which models costs against your specific goals.

How do I calculate my Google Ads budget?

Start from a goal: divide your target revenue by your target ROAS, or multiply your expected conversions by your target cost per acquisition, to get a monthly spend figure. Divide that monthly number by roughly 30 for a daily average, then check it against Google’s pacing rules so day-to-day fluctuations don’t come as a surprise.

How much should I increase my budget for the holiday season?

Google recommends planning for roughly 2x your normal target spend during peak periods, rising to as much as 3x for the heaviest holiday weeks, so Shopping and Performance Max campaigns aren’t capped just as demand rises. Start the ramp two to three weeks ahead of the peak rather than the week it begins.

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