Google Ads Performance Planner: how forecasts work and when to trust them

Google Ads Performance Planner is a forecasting tool inside Google Ads that estimates how changes to budgets and bid targets could affect clicks, conversions and conversion value over a future date range you pick. It does not change anything in your account by itself; you only see a forecast until you choose to apply the suggested changes.

In practice it is a planning tool. It is good at answering "what might happen if I spend more, or less, on these campaigns next month?" It is much weaker at answering questions it was never built for, such as whether your tracking is right or whether a new market will behave like your current one. This guide walks through what it forecasts, which campaigns qualify, how to build a plan, how to read the output, how applying changes works, and where the forecasts stop being reliable.

What Performance Planner forecasts

According to Google Ads Help, Performance Planner projects monthly and quarterly performance for the campaigns you put in a plan. The forecast covers the key metric you choose when you create the plan, such as clicks, conversions or conversion value, and you can add secondary metrics on top.

A few details are worth knowing before you trust a number:

• Conversion forecasts use the conversion actions counted in your "Conversions" column, or a conversion goal you select. Only conversion actions set as primary and attached to forecastable campaigns show up in the goal list.
• For Search and Performance Max, the tool includes conversion delay estimates, so it tries to project conversions that will land inside your conversion window rather than only those reported on the day.
• Forecasts refresh daily. Google says they are based on the last 7 to 10 days of data, adjusted for seasonality.
• The tool simulates relevant ad auctions using a very large set of search queries that is usually refreshed every 24 hours, and it takes factors such as seasonality, competitor activity and landing pages into account.
• Secondary metrics that can be shown include conversion value, ROAS, impression share and store visit metrics where they apply.

The practical reading is simple: the forecast describes how your recent account, in the recent auction, would respond to a different level of spend. It is a model of the near past projected forward.

Which campaign types and bid strategies are eligible

Performance Planner supports Search, Shopping, App, Demand Gen, Local and Performance Max campaigns. Google removed support for Display and Video campaigns from 9 March 2026, and plans that use impression share, top impression share or absolute top impression share as the key metric are no longer supported either.

Eligibility is set per campaign type. The thresholds below are taken from the Google Ads Help page on Performance Planner. They are low bars, which tells you something: a campaign can be technically forecastable with very little data behind it.

Search, Shopping and Performance Max

• No bid strategy change in the last 10 days.
• At least 3 clicks and at least 10 impressions.
• At least 1 conversion or some conversion value.
• Spend greater than zero in the last 17 days.
• If the campaign uses a portfolio bid strategy, it must be linked to a shared budget that includes every campaign using that strategy.

Demand Gen

• No bid strategy change in the past 7 days.
• For Target CPA, Maximise conversions and Maximise clicks: at least 14 impressions in the past 7 days.
• For Target ROAS and Maximise conversion value: at least 5 conversions in the past 7 days.
• Not in an experiment, not connected to a product feed, not a flighted campaign and not using mixed bid strategies.
• Campaigns bidding for conversions or value cannot plan for clicks, and Maximise clicks campaigns cannot plan for conversions or conversion value.

App campaigns

• App install ads using target cost per install or Target CPA, or app engagement ads using Target CPA.
• No bid strategy change in the last 10 days and at least 10 days of running time.
• At least 10 conversions in the last 10 days.
• Not in "Limited by budget" status.

Campaigns that miss these rules are marked unforecastable. When you build a plan you can leave them out, or include them by entering past cost and conversion figures for a date range you choose. That second option is useful for keeping the total budget picture complete, but it means the forecast for those campaigns rests on numbers you typed in, not on an auction simulation.

How to build a plan

The steps below follow the Google Ads Help article on creating and editing plans:

1. Open Performance Planner from the Tools menu in Google Ads.
2. Click the plus button to start a new plan.
3. Set the date range, the channel and the key metric, for example clicks, conversions or conversion value. You can also pick one or more conversion goals so that only data from those goals is used.
4. Optionally enter a target, such as a spend amount or a cost per acquisition. With a target set, the tool adjusts potential spend to try to reach it.
5. Select the campaigns to include. Google recommends grouping campaigns that share the same goal. Unforecastable campaigns can be excluded or added with manual past performance.
6. Click Create to open the forecast.

Google also shows suggested plans at the top of the Performance Planner page. You can review the campaigns in a suggested plan and create it from the card. Edits to a plan save automatically, and plans can be removed from the list when you no longer need them.

Two choices at the setup stage shape everything that follows. The first is campaign grouping. If you put a brand campaign that converts cheaply in the same plan as a prospecting campaign that converts slowly, the tool may shift budget toward whichever looks most efficient in its model, which may not match your business intent. Keep plans to campaigns with a shared goal. The second is the key metric. Planning for conversions when your conversion actions mix purchases with newsletter sign-ups will produce a forecast that counts both as equal, so pick a conversion goal that reflects what you actually want to buy.

For Shopping campaigns linked to several Merchant Center accounts, you can select more than one only if none is in scope of the Comparison Shopping Services program. Otherwise they have to be planned one at a time.

Reading the forecast

The forecast page has two main parts: a forecast graph and a forecast table.

The graph shows how changing overall spend could affect the combined performance of every campaign in the plan. You click points on the graph to change the spend level and see the projected result. Where the curve starts to flatten is the part to study: it shows where extra money starts buying less.

The table breaks the plan down by campaign. Each row shows forecasted spend, the key metric, related metrics and the suggested changes. Under each metric there are three columns:

• Planned: projected performance if you apply the plan's suggested settings.
• Existing: projected performance if you keep current settings.
• Diff.: the gap between Planned and Existing.

The Compare button at the top of the overview lets you set the forecast against previous time periods. Use it. If the plan forecasts a big jump in conversions at a modest budget increase, checking the same period last month or last quarter is the fastest way to see whether the forecast is in line with what the account has actually done.

Treat every forecast figure as a midpoint, not a promise. The Help pages describe these as forecasts based on recent data and auction simulation, so a range around the number is the honest way to plan. As an illustrative example only: if the table shows 400 planned conversions against 340 existing, a sensible internal plan would budget for something between the two and set a review date, rather than committing the full 400 to a sales team.

You can change spend or settings for an individual campaign by clicking it and using the side panel. One limit is easy to miss: you cannot adjust conversion rates. If you expect a landing page change or a promotion to lift conversion rate next month, Performance Planner will not include that. You have to adjust your expectations yourself.

Applying changes

Once a forecast is generated, the "Apply suggested changes" button appears at the top right of the page. The flow, as Google describes it, is:

1. Review the suggested adjustment for each campaign, such as a budget or bid target change.
2. Deselect any campaign you want to leave as it is.
3. Confirm. Live campaigns update immediately.

Changes made this way can be monitored and undone from the Bulk actions area of your Google Ads account, which is the place to check if something looks wrong the next day.

Two behaviours deserve attention before you click confirm. Performance Planner may suggest a zero budget for some campaigns or portfolios and recommend pausing them, because it judges them inefficient for the spend distribution it is modelling. That may be correct for the metric you chose and wrong for your business, for example when a campaign exists to defend a brand term or to reach a market the planner cannot value.

A cautious way to apply a plan is in stages. Apply changes to the campaigns with the most data first, leave the rest, and compare actual results against the Planned column after a week or two. If reality tracks the forecast, apply more. If it does not, you have learned something about how far to trust the tool for this account.

The limits of any forecast

Performance Planner is only as good as the inputs it can see. The main limits come straight from how Google says it works:

• Short memory. Forecasts lean on the last 7 to 10 days, adjusted for seasonality. A week with a sale, an outage or a tracking fault will colour the next plan.
• No conversion rate control. Planned changes to your site, prices or offer are invisible to the tool.
• Tracking is assumed correct. If a conversion action double counts or misses events, the forecast inherits the error and scales it.
• Low eligibility thresholds. A Search campaign with 3 clicks and 1 conversion is technically forecastable, but a forecast built on that much data carries a lot of uncertainty.
• Volatile markets. Google's own guidance is that during market volatility you should plan weekly rather than monthly or quarterly until markets settle.

When not to trust it

There are a handful of cases where the honest answer is to plan without Performance Planner, or to use it only as a rough reference.

The first is right after structural change. A campaign that has just moved to a new bid strategy, merged ad groups or swapped its conversion goal is describing a past that no longer exists. Wait until the eligibility window has passed and the data reflects the new setup.

The second is any period where your conversion rate will move for reasons the tool cannot see: a big promotion, a new checkout, a price change or a stock problem. Since conversion rate is fixed in the planner, its numbers will be off in a predictable direction.

The third is when the plan's goal and the business goal differ. If you plan for conversions but care about profit, the tool will happily move budget toward cheap, low-value conversions. Planning for conversion value, with value tracking you trust, is closer to most businesses' real objective.

The fourth is new markets or new campaigns with thin history. With so little data, even a forecastable campaign is mostly guesswork, and a test budget with a fixed review date tells you more than any forecast.

What this means for advertisers in Thailand

The mechanics of Performance Planner are the same in Thailand as anywhere else, but a few local features of the market make its limits more visible.

Thai retail demand bunches around predictable dates such as double-digit sale days, payday at month end and holiday periods like Songkran and year end. Because forecasts lean on a short window, a plan built just after one of these spikes can overstate normal demand, and a plan built in a quiet week can understate the next spike. Planning weekly around those dates, as Google suggests for volatile periods, is a sensible habit.

Finally, many Thai businesses close sales through LINE or phone calls rather than a web checkout. If those conversions are not imported back into Google Ads, Performance Planner simply cannot see them, and its forecast will undervalue the campaigns that drive them. Getting offline or messaging conversions into the account is a precondition for a useful forecast.

FAQ

Does building a plan in Performance Planner change my campaigns?

No, building or editing a plan only produces a forecast, and nothing changes in your Google Ads account unless you make the changes yourself. Spend only moves if you apply the suggested changes or edit campaigns directly.

Why is my campaign marked unforecastable?

A campaign is unforecastable when it misses the eligibility rules for its type, most often because the bid strategy changed recently or there are too few clicks, impressions or conversions. You can exclude it or add it with manually entered past cost and conversion data.

Can I still plan Display and Video campaigns?

No, Google ended Performance Planner support for Display and Video campaigns on 9 March 2026, and existing plans for them can no longer be viewed or edited. Plans that use impression share metrics as the key metric are also no longer supported.

Does applying a plan change my campaigns straight away?

Yes, once you confirm "Apply suggested changes", live campaigns update immediately. You can deselect campaigns before confirming and review or undo the changes from Bulk actions afterwards.

How often should I rebuild a plan?

Forecasts refresh daily, so an existing plan stays current, but it is worth reviewing whenever the account or market changes. Google recommends weekly planning during volatile periods instead of monthly or quarterly.

Getting a plan you can defend

Performance Planner is most useful as a structured way to ask "how much more can this account absorb, and at what cost?" before a budget meeting. It works best on stable campaigns with clean conversion tracking and a single clear goal, and it should be checked against real results after every change.

If you want a second pair of eyes on budget planning, tracking or bid strategy, our Google Ads management service covers account structure and spend planning, and the Relevant Search Google Ads programme explains how a managed search account is run. Retailers planning Shopping budgets can also look at our Google Shopping service, and accounts with weak conversion data may want to start with GA4 setup and tracking before trusting any forecast.