Company lists · Data refreshed September 2026

Top 25 Calendar scheduling software companies based in the United States

RevenueBase identified 161 calendar scheduling software companies headquartered in the United States as of September 2026 and tracks 1,518 professional contacts across them, including 521 with verified work emails. San Francisco is the largest hub.

This list covers calendar scheduling software companies headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 27, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 27, 2026 86% judged on-target in blind review
161Companies
1,518Contacts tracked
521Verified emails
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The 25 largest calendar scheduling software companies based in the United States

Ranked by team size
Top 25 of 161 calendar scheduling software companies based in the United States, ranked by team size, largest first. Data refreshed Sep 27, 2026. RevenueBase Smart Search rates how each company's information relates to calendar scheduling software companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceAtlanta, GA, United StatesHQ checked Sep 27, 2026501-1,000507 contacts →

Partial evidence

“At Calendly, our vision is to take the work out of connecting with others so you can accomplish more.”

Source: RevenueBase Database · checked Sep 27, 2026
2Partial evidenceRemote First, VA, United StatesHQ checked Sep 27, 202611-5064 contacts →

Partial evidence

“We’re on a mission to make the most of every minute, with scheduling that’s built to help reshape what’s possible for our schools, and each student within them.”

Source: RevenueBase Database · checked Sep 27, 2026
3Partial evidenceAtlanta, GA, United StatesHQ checked Sep 27, 202651-20057 contacts →

Partial evidence

“SUMO is a customer engagement platform that includes online Appointment, Event, and Field Sales scheduling, built fully native on Salesforce.”

Source: RevenueBase Database · checked Sep 27, 2026
4Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 27, 202611-5046 contacts →

Partial evidence

“Cal.com is a modern, fully customizable scheduling platform built for teams that care about both power and design.”

Source: RevenueBase Database · checked Sep 27, 2026
5Strong evidenceSeattle, WA, United StatesHQ checked Sep 27, 202651-20045 contacts →

Strong evidence

“Shiftboard is a leading provider of employee scheduling software for shift-based operations in mission-critical industries.”

Source: RevenueBase Database · checked Sep 27, 2026
6Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 27, 202651-20037 contacts →

Partial evidence

“Clockwise is an AI-powered calendar assistant that builds smarter schedules for everyone by coordinating the way individuals, teams, and companies prefer to work.”

Source: RevenueBase Database · checked Sep 27, 2026
7Partial evidenceAustin, TX, United StatesHQ checked Sep 27, 202611-5031 contacts →

Partial evidence

“Picktime is one of the world's leading scheduling platforms providing a quick, intuitive tool that enables professionals to book meetings with clients.”

Source: RevenueBase Database · checked Sep 27, 2026
8Indirect evidenceSalt Lake City, UT, United StatesHQ checked Sep 27, 202651-20030 contacts →

Indirect evidence

“Company Info History In 1984, the first Franklin Day Planner was produced, followed by a popular time management workshop.”

Source: RevenueBase Database · checked Sep 27, 2026
9Indirect evidenceWilmington, DE, United StatesHQ checked Sep 27, 202611-5029 contacts →

Indirect evidence

“TimeZest is the dispatch company for managed service providers.”

Source: RevenueBase Database · checked Sep 27, 2026
10Partial evidencePortland, OR, United StatesHQ checked Sep 27, 202651-20022 contacts →

Partial evidence

“Setmore offers a free online scheduling platform that empowers you to balance your scheduling, connect with customers, and grow your brand.”

Source: RevenueBase Database · checked Sep 27, 2026
11Partial evidenceNew York, United StatesHQ checked Sep 27, 202611-5019 contacts →

Partial evidence

“Vimcal is the world's fastest calendar, beautifully designed for people who have too many meetings.”

Source: RevenueBase Database · checked Sep 27, 2026
12Strong evidenceSan Francisco, CA, United StatesHQ checked Sep 27, 202611-5018 contacts →

Strong evidence

“AddEvent is a cutting-edge software company providing best-in-class calendar marketing and event management solutions to thousands of companies worldwide.”

Source: RevenueBase Database · checked Sep 27, 2026
13Indirect evidencePortland, OR, United StatesHQ checked Sep 27, 202611-5017 contacts →

Indirect evidence

“The important stuff doesn't happen just because you write it down.”

Source: RevenueBase Database · checked Sep 27, 2026
14Indirect evidenceSan Antonio, TX, United StatesHQ checked Sep 27, 202611-5014 contacts →

Indirect evidence

“It’s About Time… Time is more than money In your 24x7 organization, time is everything.”

Source: RevenueBase Database · checked Sep 27, 2026
15Partial evidenceCollege Station, TX, United StatesHQ checked Sep 27, 20261-1014 contacts →

Partial evidence

“Optisol is a software company located in Texas.”

Source: RevenueBase Database · checked Sep 27, 2026
16Partial evidenceKnoxville, TN, United StatesHQ checked Sep 27, 202611-5013 contacts →

Partial evidence

“The trusted partner in comprehensive B2B appointment, event, and association management software, building enduring partnerships with our clients to empower them to create…”

Source: RevenueBase Database · checked Sep 27, 2026
17Partial evidenceGrand Rapids, MI, United StatesHQ checked Sep 27, 202611-5012 contacts →

Partial evidence

“SCHEDULING The heart of SKED is the amazing control and flexibility of your scheduling.”

Source: RevenueBase Database · checked Sep 27, 2026
18Partial evidenceCharlotte, NC, United StatesHQ checked Sep 27, 20261-1011 contacts →

Partial evidence

“TimeTap Online Scheduling is a simple & effective tool for the multifaceted and over-stressed life of service providers & appointment based businesses.”

Source: RevenueBase Database · checked Sep 27, 2026
19Partial evidenceSpokane, WA, United StatesHQ checked Sep 27, 202611-5011 contacts →

Partial evidence

“We are Calendar, trying to make the world a much more productive place.”

Source: RevenueBase Database · checked Sep 27, 2026
20Strong evidenceNew York, NY, United StatesHQ checked Sep 27, 20261,001-5,00011 contacts →

Strong evidence

“Flexible scheduling software designed to help you grow, because booking time should never get in the way of success.”

Source: RevenueBase Database · checked Sep 27, 2026
21Partial evidenceSan Francisco, CA, United StatesHQ checked Sep 27, 20261-109 contacts →

Partial evidence

“Every scheduling tool books by availability, whoever grabs the open slot wins.”

Source: RevenueBase Database · checked Sep 27, 2026
22Partial evidenceFargo, ND, United StatesHQ checked Sep 27, 202611-509 contacts →

Partial evidence

“Atlas Business Solutions, Inc.(ABS) develops easy and affordable software for small businesses that help them save time and streamline business processes.”

Source: RevenueBase Database · checked Sep 27, 2026
23Indirect evidenceAventura, United StatesHQ checked Sep 27, 202611-509 contacts →

Indirect evidence

“Shifton is a multi-functional online solution which ensures stable workflow within a company.”

Source: RevenueBase Database · checked Sep 27, 2026
24Indirect evidenceTampa, FL, United StatesHQ checked Sep 27, 202651-2007 contacts →

Indirect evidence

“Our History We started our construction company 18 years ago, specializing in concrete and masonry.”

Source: RevenueBase Database · checked Sep 27, 2026
25Strong evidenceScottsdale, AZ, United StatesHQ checked Sep 27, 202651-2006 contacts →

Strong evidence

“StormSource Software, which does business as AppointmentPlus, is a worldwide leader in online scheduling solutions for growing businesses, enterprises, higher education…”

Source: RevenueBase Database · checked Sep 27, 2026

Showing 25 of 161 calendar scheduling software companies based in the United States

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Calendar scheduling software companies based in the United States at a glance

As of Sep 27, 2026
34.3%Verified-email coverage
9.4Average contacts per company
1-10Median size (employees)
9.9%Largest-city concentration · San Francisco
Sep 27, 2026Page data refreshed

Companies by employee count

1-10
106
11-50
40
51-200
10
201-500
2
501-1,000
2
1,001-5,000
1

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 161 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among calendar scheduling software companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “calendar scheduling software companies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names calendar scheduling software companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among calendar scheduling software companies, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 521 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 27, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names calendar scheduling software companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many calendar scheduling software companies are there based in the United States?

RevenueBase identified 161 calendar scheduling software companies headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Calendly, headquartered in Atlanta, tops this list with the largest team on record.

Which city has the most calendar scheduling software companies?

San Francisco leads with 16 headquartered companies, followed by New York (10) and Austin (7).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 521 verified decision-maker contacts tracked across these 161 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 27, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.