Castos
Free Podcast Tool

Free Podcast Advertising Calculator

See what your show could earn from dynamic ads. Set your monthly downloads, CPM, and fill rate to estimate your podcast ad revenue.

Estimate Your Podcast Ad Revenue

Move the sliders to match your show. The numbers update as you go.

5,000

Downloads across your whole show, not per episode.

2

Castos Ads runs two, a pre-roll and a post-roll.

30%

How often a spot gets filled. Varies by genre, location, and demand.

$10

What advertisers pay per thousand ads heard. Usually $5 to $20.

Estimated monthly earnings

$30

Per year

$360

An estimate, not a quote. Campaigns runs promos and announcements too, not just ads. See how Campaigns works →

Start earning from your back catalog

Castos Ads filled about 1.3 million ad impressions for shows on Castos in the first half of 2026.

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What Affects A Podcast Advertising Calculator's Results?

CPM

Cost Per Mille (or Thousand) is the rate at which you are paid per ad unit. For programmatic ads this usually lands somewhere between $5 and $20. For "baked in" ads it can be a lot higher.

Fill Rate

Even with dynamic ad insertion your listeners won't always hear an ad. Fill moves with your genre, your audience location, and how much advertisers are spending that month. It decides your earnings more than CPM does.

Listens

How many times a month your podcast gets listened to, counting every episode rather than just the new ones. Listens multiplied by ad spots is the inventory you have to sell, before fill takes its cut.

Where Your Listeners Are

Advertiser demand is not spread evenly. Most of it still sits in the US, with solid and growing demand in Canada, the UK, Germany, and Spain. If your audience listens from elsewhere, expect lower fill even when CPMs look healthy.

Fill Your Entire Back Catalog

Dynamic ad insertion works on everything you have published, not just new episodes. Switch Castos Ads on and an episode from three years ago becomes ad inventory exactly like the one you release tomorrow.

Setup Takes Minutes

No need to record special segments or alter your editing process. Switch Castos Ads on in your dashboard, verify a PayPal address for payouts, and Castos takes care of the ad inventory, the stitching into your existing files, and the reporting on what you earn.

Brand Safe For Your Show

Ad content is screened for brand safety before it ever reaches your show, so you never have to vet advertisers or wonder what is playing alongside your episodes.

How To Make Money From Podcast Ads In 3 Steps

  1. Upload a new episode in Castos

    Upload A New Episode

    Publish your episodes just as you would normally. Nothing about your recording, editing, or publishing process needs to change to take advantage of the Castos Ads platform.

  2. Turn on Castos Ads in your dashboard

    Turn On Castos Ads

    Switching Castos Ads on in your dashboard enrolls you in the program. Your entire back catalog joins the marketplace, along with every new episode you publish from then on.

  3. Earn revenue from Castos Ads

    Make Money

    The Castos Ads system determines the best ads to splice into your episodes (pre-roll and post-roll) to match your audience, content, and brand, maximizing CPM.

Frequently Asked Questions

How much do podcast ads pay?
Podcast ads are priced per thousand ads heard, a rate called CPM. Programmatic rates usually run $5 to $20, and sponsorships you sell yourself go higher. What you take home depends less on that rate than on your fill rate, which is how many of your spots actually get sold in a given month. The calculator above shows the range for your show.
What is a good CPM for a podcast?
Anywhere from $5 to $20 is normal for programmatic ads, and host-read sponsorships you sell direct typically go for more. A high CPM on its own does not mean high earnings. A strong rate in a market where few advertisers are buying still leaves most of your spots empty, which is why fill rate matters more than the headline number.
How does Castos Ads work?
Castos Ads opens two ad slots in every episode, one before your content and one after, across your whole back catalog. Insertion is dynamic, so an ad is matched to each listener at download time rather than baked into your audio file. That also means a slot only earns when there is an advertiser buying for that listener, so expect some of them to go unfilled.
Do I need a minimum listener count to start monetizing?
No. Castos Ads has no minimum audience size, so you can start earning from your first episode instead of waiting to clear the download threshold traditional sponsorships ask for. Payouts begin once your balance reaches $10.
Can I monetize my entire podcast catalog?
Yes. Every episode you have already published starts earning the moment you switch Castos Ads on, alongside everything you publish afterward. For most shows the back catalog is the most underused asset they have.
Can I run my own sponsors alongside Castos Ads?
Yes, and the two stack. Castos Campaigns lets you drop a sponsor you sold into a pre-roll and post-roll across your catalog, on a schedule you set. That revenue is entirely yours and sits on top of whatever the marketplace fills.
What affects how much I earn from podcast ads?
Four things: how many people listen, how many ad spots each episode carries, what advertisers pay per thousand ads, and how many of those spots get filled. Fill rate usually moves the number most, and it depends heavily on where your listeners are, since advertiser demand is concentrated in a handful of countries.
Does Castos Ads work with video podcasts?
No. Dynamic ad insertion works on MP3 audio only, so video episodes cannot carry Castos Ads. If your show publishes both, the audio episodes still earn.
Do I need to change how I record or edit my episodes?
No. Ads are inserted at download time rather than baked into your file, so nothing about your recording, editing, or publishing changes and your original audio quality is untouched.
Is there a minimum episode length for podcast ads?
No. Short episodes are eligible for dynamic ad insertion alongside longer ones, with no minimum length to clear first.

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