Free Decennial Periods Calculator
Decennials walk through the seven classical planets in fixed Chaldean order — Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon — starting from whichever planet rules your natal Ascendant sign, each one holding its traditional "mean years" allotment before handing off to the next. This calculator finds your starting ruler, lays out the full sequence with hand-off ages, and marks which planet is running right now.How it works ↓
Calculating your placements…
Decennials walk through the seven classical planets in a fixed Chaldean order (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon) starting from your natal Ascendant's ruling planet, each planet holding its traditional "mean years" allotment before handing off to the next. It's a simpler, sect-independent companion to firdaria: one steady rotation of planetary rulership across your lifetime.
Your sequence starts from your Ascendant's ruler
The page now names your actual starting ruler — the classical planet that governs your natal Ascendant sign — instead of only describing the rule in the abstract. From that planet, the sequence proceeds through the fixed Chaldean order (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon), wrapping back around if you live long enough to complete a full pass.
Each planet holds a different, fixed number of years
Unlike profections' flat twelve-year cycle, decennial periods are unequal: Saturn holds 30 years, Jupiter 12, Mars 15, the Sun 19, Venus 8, Mercury 20, and the Moon 25. These "mean years" are fixed by tradition regardless of where the planet sits in your chart — only the starting point and the order change from person to person, not the lengths.
The hand-off ages compound from your starting ruler
Because the allotments are unequal, the age at which each planet takes over depends on the full run of planets before it in your sequence, not just a fixed multiple of years. The calculator adds up each period's mean years in order from your starting ruler so you can see the exact age each planet's period begins.
A full pass through all seven planets covers 129 years
The seven mean-years allotments sum to 129 years, so most charts only ever move partway through one pass — but the order always begins wherever your Ascendant ruler falls in the Chaldean sequence, not necessarily with Saturn.
Decennials sit between profections and firdaria in complexity
Profections recount your Ascendant sign every year on a flat cycle, and firdaria's lord order depends on sect — decennials split the difference: the starting point comes from your Ascendant like profections, but the period lengths are fixed and unequal like firdaria's. Run annual-profections alongside this one for the simpler yearly view, or firdaria for the sect-based one.
Frequently Asked Questions
Which planet starts my decennial sequence?
Whichever classical planet rules your natal Ascendant sign. The page names your actual starting ruler directly rather than just describing the rule.
How many years does each planet get in decennials?
A fixed allotment set by tradition: Saturn 30, Jupiter 12, Mars 15, Sun 19, Venus 8, Mercury 20, Moon 25 — the same lengths for everyone, only the starting planet and hand-off ages change.
What order do the decennial planets follow?
The fixed Chaldean order — Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon — beginning from your Ascendant's ruler and wrapping back around if the sequence runs past 129 years.