PMP formulas you have to know

When taking the PMP exam, you can expect to answer different types of questions: formula-based questions, situation-based questions, definition-based questions, ITTO-based questions, interpretational questions and PMP ethics questions.

Different types of questions need a different approach. For me personally, it's easier to calculate, and formula-based questions were my favorite during the preparation for the exam. I made a list of all formulas used in project management and learned them by heart. I will share this list and also, I will show you my cheat sheet of the formulas that I actually used during the exam.

Formula	Definition	Abbreviations	Note
PV = Planned % Complete * BAC	What the project should be worth	PV - planned value BAC - budget at completion
EV = Actual % Complete * BAC	What the project is worth	EV - earned value BAC - budget at completion
SD = (P - O) / 6	SD measures the Variation from Average	SD - standard deviation P - pessimistic estimate O - optimistic estimate
EAD = (O + 4R + P) / 6	EAD calculated by beta distribution	EAD - estimated activity duration R - realistic estimate P - pessimistic estimate O - optimistic estimate
EAD = (O + R + P) / 3	EAD calculated by triangular distribution	EAD - estimated activity duration R - realistic estimate P - pessimistic estimate O - optimistic estimate
CV = EV - AC	CV represents the amount of budget deficit or surplus at a given point in time	CV - cost variance EV - earned value AC - actual cost
SV = EV - PV	SV aims to measure schedule performance through the difference between the earned value and the planned value	SV - schedule variance EV - earned value PV - planned value
CPI = EV / AC	CPI measures the cost efficiency of budgeted resources	CPI - cost performance index EV - earned value AC - actual cost
SPI = EV / PV	SPI measures schedule efficiency	SPI - schedule performance index EV - earned value PV - planned value
ETC = EAC - AC	ETC predicts how much more the remainder of the project will cost	ETC - estimate to complete EAC - estimate at completion AC - actual cost
EAC = BAC / CPI	Predicts final project costs based on current performance	EAC - estimate at completion BAC - budget at completion CPI - cost performance index
EAC = AC + BAC - EV	Predicts final project costs based on current performance	EAC - estimate at completion BAC - budget at completion AC - actual cost EV - earned value
EAC = AC + [(BAC - EV) / (CPI * SPI)]	Predicts final project costs based on current performance	EAC - estimate at completion BAC - budget at completion AC - actual cost EV - earned value CPI - cost performance index SPI - schedule performance index
VAC = BAC - EAC	VAC is a projection of the amount of budget deficit or surplus	VAC - variance at completion BAC - budget at completion EAC - estimate at completion
TCPI = (BAC - EV) / (BAC - AC)	Predicts likelihood of reaching BAC	TCPI - to-complete performance index BAC - budget at completion EV - earned value AC - actual cost
TCPI = (BAC - EV) / (EAC - AC)	Predicts likelihood of reaching EAC	TCPI - to-complete performance index BAC - budget at completion EV - earned value AC - actual cost EAC - estimate at completion
N * (N - 1) / 2	Number of communication channels	N - number of team members
Slack = LS - ES	Date constraints, within which we can plan our activity without affecting the overall length of the project	LS - late start ES - early start
Slack = LF - EF	Date constraints, within which we can plan our activity without affecting the overall length of the project	LF - late finish EF - early finish
EF = ES + Duration - 1	The earliest you can finish the activity without delaying the project end date	EF - early finish ES - early start
LS = LF - Duration + 1	The latest you can start the activity without delaying the project end date	LS - late start LF - late finish
EMV = Probability * Impact	EMV represents the expected money to be made from a specific decision	EMV - expected monetary value
ROI = (Net Profit / COI) * 100	Measures profit or loss gained through an investment based on the amount invested	ROI - return on investment COI - cost of investment
CBR = NPV / initial investment cost	CBR tells about the profit to be received from an investment	CBR - cost-benefit ratio NPV - net present value
NPV = Value / (1 + r) ^ t	Net present value of investment	Value - value of benefits r - rate of discount t - defined time frame

This is the most complete list of formulas I could make for myself. I knew all of them and I definitely recommend you learning them all without exception. However, some of them are used more often than others.

On the PMP exam, it's highly effective to write a cheat sheet as soon as the exam starts. It's a concise set of notes used for quick reference. In my cheat sheet I included the most commonly used formulas. From my personal experience, all the formulas that I needed on the exam were on this list. But this is only my experience and you never know what sorts of questions you will have and what formulas you will have to use. That's why, even though most probably you will use the formulas mentioned in my cheat sheet, you should not limit yourself to only them, but learn all the formulas used in project management.