The Five Elements are Wood, Fire, Earth, Metal and Water, five basic kinds of qi that Chinese tradition uses to describe the nature of things and how they change. In BaZi, every Heavenly Stem and every Earthly Branch belongs to one element, and each stem is also Yin or Yang.

Each Earthly Branch also hides one to three Heavenly Stems, known as Hidden Stems. The main one is the primary qi, and the others are the middle and residual qi. For example, Yin (Tiger) hides Jia, Bing and Wu: it's mainly Wood, with a little Fire and Earth. That's why you can't judge the elements just by counting the eight visible characters.

The elements relate to each other in two basic ways:

• Producing Cycle: Wood feeds Fire, Fire makes Earth, Earth yields Metal, Metal carries Water and Water nourishes Wood. Think of it as a nurturing, passing-on relationship.
• Controlling Cycle: Wood breaks Earth, Earth contains Water, Water puts out Fire, Fire melts Metal and Metal cuts Wood. Think of it as a restraining, managing relationship.

Neither producing nor controlling is simply good or bad. Without producing, energy can't continue; without controlling, it can run out of hand. The Ten Gods in BaZi come straight from these two cycles. See Ten Gods for Beginners.

The same element has different strength in different seasons: Wood is strongest in spring, Fire in summer, Metal in autumn and Water in winter. BaZi uses the branch of your birth month, called the month command (Yue Ling, 月令), to stand for the season. The Day Master's element can be in one of five states compared with it: thriving (Wang) when it's the same element, supported (Xiang) when the season produces it, resting (Xiu) when it produces the season, confined (Qiu) when it controls the season and dormant (Si) when the season controls it.

Our calculator gives the month command a lot of weight in two places:

• Element balance: each of the four Heavenly Stems scores 12 points, the year, day and hour branches score 12 points each and the month branch alone scores 40, for 124 points in total. Each branch's points are then shared among its primary, middle and residual qi. The month command alone accounts for about a third.
• Day Master strength: first we check which seasonal state the Day Master is in (thriving and supported add points; confined and dormant take points away), then whether it has roots in the branches, and finally we compare the elements that support it (its own element and the one that produces it) with those that drain it (the ones it produces, controls or is controlled by). The result is one of five levels: Strong, Slightly Strong, Balanced, Slightly Weak or Weak.

Favourable Elements (Xi Yong Shen, 喜用神) are the elements that help a chart most. We first set the direction with the Support & Restrain approach, then check warmth and coolness with Climate Balance, and finally choose two elements as your Favourable Elements:

• Strong or Slightly Strong Day Master: there's energy to spare, so it helps to give it an outlet. We choose from the elements the Day Master produces (Output), controls (Wealth) or is controlled by (Officer).
• Weak or Slightly Weak Day Master: there's less energy, so it helps to top it up. We choose the element that produces the Day Master (Resource) and its own element (Peers).
• Balanced Day Master, but born in the cold Hai, Zi or Chou months or the hot Si, Wu or Wei months: we balance the temperature first, choosing Fire for winter and Water for summer, paired with the element that produces it (Wood with Fire, Metal with Water).
• Balanced Day Master in a mild season: we choose the two weakest elements in the chart so the elements flow more smoothly.

When Support & Restrain and Climate Balance both apply, here's what we do. If the element the climate needs is also one of the Support & Restrain choices, it goes first, because it does both jobs. If the two point in different directions, Support & Restrain takes priority and decides the Favourable Elements, and the result notes the climate element as a supporting reference. That keeps the explanation consistent from start to finish.

Apart from the Favourable Elements, the strongest element in a chart is usually seen as one to keep in moderation. Our Free BaZi Calculator shows your element balance, chart strength and Favourable Elements, and the Full Chart shows how your Favourable Elements rise and fall through your Luck Pillars and Annual Pillars.

The Five Elements are a way of looking at balance, not a verdict on your life. Your Favourable Elements can remind you where to put a little more energy, such as learning, expressing yourself, building up resources or giving yourself more stability. They can't replace effort, professional advice or real life experience. If you'd like to learn BaZi step by step from the Day Master, start with What is the Day Master?