Charlie Brown wah wah wah

How to Increase the Response Rates on Your Next Fundraising Appeal by Lowering Your F-K Score

Are your donors smarter than a 5th grader?

Obviously, yes.

But I also want to know, what do your donors do in their free time?

And, do you think they want to spend it reading long-winded or complicated appeals?

Would you?

To make it easy for donors to know how their gift will make a positive impact, lower the F-K Score.

What is an F-K Score?

F-K scores, or grade-level equivalents, were first developed in 1975 by Rudolph Flesch, an author and writing consultant, and John P. Kincaid, a scientist and educator. (Hence the “Flesch-Kincaid” or F-K score.)

Originally, Flesch and Kincaid created this readability scale to make sure sailors could easily understand the technical manuals on ships.

No sense in having manuals if sailors couldn’t understand what they were reading.

And it’s not just in technical writing! Some of the greatest authors in history famously wrote with low F-K scores…

J.D. Salinger’s The Catcher in the Rye has an F-K score of 4.7, and Ernest Hemingway also wrote at a 4th-grade reading level.

This “readability” concept applies to the fundraising world as well. If you make your donors think too hard, they’ll simply delete your message instead.

What do F-K scores have to do with fundraising? 

I recently wrote an appeal on behalf of a nonprofit board member. Let’s call him Ethan.

Ethan was an AMAZING person with an impressive professional career. He seemed to effortlessly balance his family life, work-life, and volunteer service.

Unfortunately, he also felt like he had to share all this information and accolades in the fundraising appeal itself.

Now you and I both know that no one cares about you, your board members, or your organization for that matter.

However, donors do care about making a difference. They want to help people. Work towards a greater mission. Join a movement.

They want to feel significant. 

But this board member – great as he was – didn’t know about fundraising language or structure…

And he promptly smashed my lovely draft to smithereens.

In fact, he added in so much about himself and “how honored he was to serve” that it was long and…boring.

Thick paragraphs.

Very little white space.

And it was all about him instead of the people he was trying to help.

Ethan’s appeal had an FK score of 12.8, as in someone had to be in college to understand it.

Does that sound like something you would want to read as you casually check your email at night?

See for yourself:

“No one is immune to the effects of COVID-19, and as the reach of this pandemic continues to widen and deepen, we are hearing how families are finding themselves faced with unprecedented financial hardships and limitations as industries are shuttered and businesses closed.”

I look at that and hear Charlie Brown’s teacher, “Wah wah wah wah waaaah.”

F-K score for that paragraph?


A 21st-grade reading level. I didn’t even know it could go that high.

Let’s pretend Ethan had taken my original suggestion and said something like…

“We know families are suffering right now, and that there’s no end in sight. Our community members have lost jobs, closed their businesses, and wondered if they can cover their basic needs.”

It says essentially the same thing, but it’s clear. It’s concise. It paints a picture that you can read quickly and understand instantly.

F-K score of the second example?

7.6. Written for a middle schooler.

Listen, I lost the battle and the appeal went out with an overall F-K score of 12.8. So did the organization raise a bunch of money anyway?


But, did they also leave money on the table? Probably also yes, although we’ll never know how much.

How should you write fundraising appeals?

First of all, don’t talk to your donors like they’re professors – speak to them like a middle school student.

For example, by using shorter sentences and common words, your reader can understand your message without thinking twice.

This will lower your F-K Score, increase readability, and inspire a greater response.

Take this example, with an F-K score of 15.5:

“Thank you for being part of this incredibly caring and resilient community, and it is a true honor to hold a leadership role to help steward the organization through this time.”

Hard to get through, right?

Now read it with an F-K score of 4.9:

“We’re in this together. I’m so grateful for your support in helping to keep our community full.”

Give your donors the gift of clear, concise, and compelling copy and they will reward your cause with a generous gift of their own.

How to check your FK Score

Copy and paste your appeal into a program such as the WebFX Readability Test Tool (available here for free, no sign-in required). Your “F-K Score” will spit out instantly.

Now, edit as needed until it’s where you want it.

To lower your FK score:

  1. Pretend you’re having a conversation with a friend over coffee
  2. Use a voice-to-text program to transcribe your “conversation”
  3. Write like you talk (avoid jargon)
  4. Anywhere you see an “and,” try to break it into two sentences
  5. Replace 3- or 4-syllable words with 1- or 2-syllable words
  6. Inject fragments
  7. Write short sentences – under 20 syllables if possible, and definitely under 30.

Remember, you’re not “dumbing” down your copy by lowering the F-K score. Rather, you’re making it easier for your reader to absorb the content quickly. 

No one – and I do mean no one – should ever assume their donors are too smart, too serious, or too ‘important’ to appreciate an engaging, easy-to-read letter.

So give it a try. Plug in your last appeal and establish a baseline F-K score. Then, play around a bit and analyze the results.

Just for fun – this article has an F-K score of 5.8. Do you have questions on how to improve your F-K score and increase your next fundraising appeal performance? Email me. I would love to help!